It was probably LESS THAN Interest Only, an “Option ARM.”
An artificially low payment that doesn’t even cover the interest, but when the loan balance increases to where it’s more than about 115% of the original amount, you have to start paying back principal plus all the month’s interest.
thanks. I just now read about “option ARM”. Man, what a freaking scam. It sure sounds like that that’s what that lady had. The math fits.