Are we not understating the loss somewhat? The $700 of rent under her payment seems to be added back in but what about selling costs? Also realistically, every payment made prior to her renting it out might as well be added to the loss.
And let’s not forget the California phenomenon of not counting the property tax as part of the monthly expense since most seem to pay it as one or two lump sums. In this seller’s case, if Property tax was factored into her mortgage payment then it doesn’t matter.