Something odd here. IRS does not just suddenly attach/levy bank accounts. There’s a system of assessments and notices that come weeks apart before they levy. The underlying assessment may be incorrect, but it’s highly improbable that one learns about it for the first time after the levy. My guess is that she did not properly report the property sale (even if there’s no taxable gain, you still need to report the sale because the escrow agent filed a 1099 to report the proceeds) until after the levy and then the IRS wiped out the assessment. And, I doubt that IRS admitted to being “mistaken.” Her account of the situation is possible, but not probable.
This goes way back. Please do a little research (or at least read ALL the article) before wildly speculating.