It depend of the scenario.
If it's the classical naive mother, she must be at least 18+age oldest child, it should even be 21 in the USA. There's just no way that a girl as naive as she is as a mother, had sex before this age. And there's no reason for a young slut to turn completely naive regarding sex.
The same 18+age oldest child apply for a more aware mother if she haven't had a boyfriend since years, or even never had after the father left. Here again, a young slut don't turn to celibacy by magic.
Then, if it's an old slut, she must be at least 15+age oldest child. But she also need to have had more than one boyfriend, even if she's single when the game start.
For all other cases, it should be at least 17+age oldest child.
I'm currently working on a project and I don't know if I should keep this marks or not. I don't mind them but I don't know about the rest
For me you should keep it. For once it's not the body of a 15yo girls used for a woman supposed to be over 30 yo
