A judge said Amanda Webber, 43, who was responsible for one of the biggest single benefit fraud overpayments recorded, took advantage of the benefits system.
She fooled authorities by making claims on the basis that five of her eight children suffered disabilities and conditions which affected their care and mobility needs, a five-week trial at Brighton Crown Court heard.
Prosecutors said that despite their reputed health problems, the children led active lives, taking part in PE classes and activities including music, drama and dance without difficulties - and some auditioned for ITV's Britain's Got Talent.
Some also attended fee-paying schools and performed in professional productions on television and on stage, including Les Miserables, The Wizard Of Oz and Billy Elliot, jurors heard.
Webber, from Sussex, was found guilty of 23 out of 24 charges, including fraud, obtaining a money transfer by deception and obtaining property by deception. She was cleared of one count of making a false representation.
The false payments related to disability living allowance (DLA), carer's allowance, tax credits and housing and council tax benefit. Sentencing her, Judge Anthony Niblett said Webber and her family had at one point an income of more than £10,000 a month.
The judge told her: "This is an income which the vast majority of your hard-working, honest fellow citizens can only dream of." He added: "These benefits included private education and every material advantage ... including a grand piano and a dance studio in your last home, so as to encourage the undoubted talents of some of your children."
Judge Niblett said Webber was "undoubtedly a highly intelligent woman" who had taken advantage of the benefits system. Prosecutor Andrew Evans said the Crown would look at launching confiscation proceedings against Webber to recover some of the money.