my wife paid the IRS $20,000 in taxes and now they want more.
I herd that she could be fined for not paying a little along.
You can still be subject to an underpayment penalty even if you did make quarterly payments. If you didn't pay enough for each quarter, then an underpayment penalty can still be assessed. For more information see https://www.irs.gov/payments/underpayment-of-estimated-tax-by-individuals-penalty
