The problem would not be whether she was a virgin or not; if that were the problem, then people would not be interested in MILFs. Nor is it a problem that she was a prostitute.
What bothers people is that the character engages in sexual activities with other men in the present. No one is bothered by the past, but it is annoying to get to know her and then see her leaving a hotel with another man, knowing what she does for a living. It doesn’t matter if it’s a realistic story, no one likes it when the girl they are interested in at that moment is a fictional character and something happens that they don’t like, since you are playing the protagonist, it’s disappointing, but oh well. That’s my opinion.