It is her responsibility to do any necessary research about your finances…to demand any necessary tax records, pay stubs, bank records, prior to signing the agreement. Ignorance because she just signed on the dotted line without taking the time to review stuff isn’t grounds for overturning a contract.
Basically, all a SA is is a contract, plain and simple and many of the rules regarding contract law apply. So, regular “ignorance” isn’t really an excuse. Now, being “ignorant” because someone was deliberately defrauding you, is a separate issue. Criminal and willful behaviour that defrauds the signor resulting in their ignorance, is potential grounds for overturning a contract. So, if she asked you for pay stubs, and you provided doctored or false ones, then it is fraud and she has grounds to overturn.
If you put a gun to her head and forced her to sign, then it is duress and she can get it overturned. Likewise, if she lacked the mental capacity through insanity to understand what she was signing and was therefore ignorant, then it really isn’t a viable contract. Inability to perform I covered in my previous post.
Mistakes in reported amounts of money like “oh, I didn’t remember about that bank account that my mother set up for me when I was 12 with $20 that has now grown to $500,” aren’t really grounds to overturn. It has to be a deliberate attempt to deceive, as in hiding of assets and lying about hiding them.