If she is a single mother she is probably slutting it out.
If she is older committed married mother she is doing with her husband, and heck, they might be even years were they go by without doing it. Though, she might come over as being asexual. Yeah you got birthed, and your sibling got birth, but who wants to thing of sex and their parents. Also as she gets old, she cant get pregnant.
If she is older committed married mother and active with her husband, then her tubes are tied and they bucking like cray
Also, you could tell if a mom is slut or believe in sluttism with how she raises her daughters