On this occasion, though, the family had something special to celebrate at the end of the appointment.
"Today was an extra special day as the treatment has now finished and we had brilliant results from this," says Zara.
The family was in high spirits, and explained to the waitress, Jo, why they were all in such a good mood as they ordered their meal.
"She was amazed at our story and congratulated us," says Zara.
But after ordering a burger and mash and a chicken pitta with chips and rice, the family had a pleasant surprise.
"We then placed our order and went to pay and she explained that the restaurant will take care of our bill as they wanted us to enjoy this moment," says Zara, thanking the company on Facebook.
The £32.75 'discount' was listed on the bill as a 'random act of kindness', leaving nothing for the family to pay.
Nando's has been waiving the cost of certain people's meals, or giving discounts, for several years now, with the 'random act of kindness' explanation on the bill. It's also been giving A-level students free meals on results day.
And as one other visitor to the Nando's page points out, "That cost Nando's next to nothing, but the good publicity from it is worth its weight in gold. Good service from a chain restaurant makes a refreshing change."
Cosmetic company Lush has a similar policy - and says it can improve the morale of staff as well as customers.
"Acts of kindness can be completely reactive, and they could have a huge impact on someone else," says the company's Katie Dancey-Downs. "By asking people to 'pay it forward', seemingly random ripples of kindness could set off waves of good deeds."
Unusual restaurants around London
Unusual restaurants around London
You can dine in pitch darkness at Dans Le Noir (In The Dark). Guided and served by blind people, you'll be treated to a 'surprise menu', which will tantalise your senses of taste and smell the nature of which is only revealed after your meal is finished.
Dinner with a view is always an attractive option but did you ever think you'd be able to eat while suspended above the London skyline? Well now you can! Dinner in the Sky operates in 43 different countries around the world and offers diners the once in a lifetime opportunity to eat on board one of the trademarked sky platforms 100 ft in the air.
Enjoy doodling and love good food? Then Doodle Bar in Bermondsey is the place for you! Here you have the chance to enjoy some top quality street food in the outdoor 'beach' area before heading back inside to have a good old fashioned doodle on the walls. This creative space may not be easy to spot though, look out for the neon 'bar' sign that highlights the entrance.
Described as a "collision of cabaret restaurant and cocktail bar", Circus offers a unique dining experience. As well as fabulous food you'll have the opportunity to watch a number of top class performances in between courses. Circus can be found right in the heart of London's theatre district and is a must for fans of everything dramatic!
The Cereal Killer Cafe is the the UK's first speciality cereal cafe. Northern Irish twins Alan and Gary Keely started the unusual venture last year and have since opened a second cafe in Camden. Diners can expect a choice of over 120 cereals, 30 varieties of milk and 20 different toppings to add to the sugar content on your meal!
Powderkeg Diplomacy in Clapham is a self-confessed combination of 'colonial Britian, Victoriana and hints of the industrial'. With repurposed gramophones hanging from the ceilings and antique decor throughout visitors can expect a menu of seasonal dishes made up with ingredients sourced solely from the United Kingdom and 'inspired by centuries of great British recipes'.
You might think you've eaten at all of London's hotspots, but have you ever had dinner in a decommissioned Victoria Line underground carriage from 1967? Basement Galley originally started out as a secret supper club but now it's a hive of social interaction across London and guests can enjoy a meal from Cordon Bleu trained chef, Alex Cooper.
Inamo is a unique Asian fusion restaurant where patrons are in charge of their own dining experience. Forget about trying to flag down a stressed out waiter in a packed restaurant, at Inamo you can place your order from the menu that is projected onto your table. But don't panic, there are still staff on hand to help you decipher some of the more complicated meals!
Barts is London's worst kept secret - an exclusive, late night speakeasy bar run by Chicago gangsters but mysteriously found somewhere in the depths of Chelsea. Under the guise of keeping this one of a kind bar secret, the exterior is dressed up as a regular London flat and you won't be allowed over the threshold unless you have a password...
At Rango's Hot Stone Kitchen you're guaranteed to get your steak just the way you like it because you'll be cooking it yourself! The restaurant has modernised the traditional hot stone cooking techniques of pre-historic stone pits found in Australia, New Zealand and South Africa and each diner is given a piping hot stone sitting on a custom made bamboo board. Rango's offers the opportunity to experience the DIY side of fine dining.
Ever eaten on top of a multi-storey car park? If you haven't, now is your chance. Frank's Cafe in Peckham was designed by Practice Architecture and opened in 2008. Not only does the cafe source the best seasonal produce for diners to enjoy but the cafe also boasts unrivalled views of the capital although admittedly from a rather unusual vantage point!
Step into the wilds of South Africa as you enter Shaka Zulu in Camden. It's the capital's largest South African restaurant and has even had royal blessing from the Zulu King, HRH Goodwill Zwelithini. As you enjoy the true essence of a South African meal you'll have the chance to marvel at the stunning braai (barbecue) restaurant decorated with carved wooden murals.
If you're looking for a champagne bar with a difference, Bubbledogs is it. Found in the heart of London's Fitzrovia just behind Tottenham Court Road, there isn't a plate of caviar in sight at this quirky restaurant. Instead of the traditional champagne accompaniments you'll have the choice of nearly 20 different types of hot dog to go along with your bubbles.
Fu Manchu is named after the infamous 1930s fictional character created by British author Sax Rohmer. The Clapham based bar is an self-confessed 'Edwardian/Opium den themed restaurant, cocktail bar and nightclub'. You can enjoy authentic homemade Dim Sum with cocktails before the lights drop and the building converts into a nightclub.
Want to play Ping Pong on an official London Olympic 2012 table? Well at Bounce, you can do just that after you've eaten at the open counter pizza restaurant while sipping on one of their many cocktails. The 12,000 sq ft venue has 17 bespoke designed ping pong tables as well as a unique restaurant and cocktail bar.
Spend the day exploring David Shrigley's works of art or indulge in a light afternoon tea... at Sketch you can do both, at the same time, in the same place. Not only does the Michelin starred restaurant offer a deliciously tempting menu but it is also home to some fine works of art for diners to browse.
Be prepared to enter a world of drama and excitement when you step through the doors of Sarastro on Drury Lane. The opulence you'll find inside echoes the drama of the theatre district of London, which is where Sarastro can be found. Opera boxes occupy three of the four walls and decorative balconies and banisters from the Royal Opera House feature throughout.
Described as the 'Englishman's Italian', Bunga Bunga pays homage to cliches of the Italian lifestyle with red and white striped gondola poles, checked table cloths and even Vespa scooters hanging from the ceiling. Diners can enjoy the Bellini Brunch, private parties or even a few rounds of karaoke.
Far Rockaway is an American-style bar and restaurant which has been inspired by the street and art culture found in the USA. It may be just off the High Street in Shoreditch but Far Rockaway serves a menu which takes inspiration from New York City. With eccentric decor, mismatched furniture and fascinating wall art, you definitely won't forget an evening spent at this American haven.
Gingerline is a 'nomadic restaurant and art space' which opens in secret locations across the London rail network. Run by adventure-loving food fanatics, Gingerline now has its first permanent location 'The Secret Island'. Previous themed events have included Planet Gingerline (pictured), and a Gothic Christmas special.