I don't think this is any big deal. It's father / daughter first of all. Doubtful they have an illicit relationship that is just now surfacing. And second, it's an ankle rub. Hardly a sexy spot. My kids are pre teens. They give me back rubs and whatnot all the time. I've seen my cousin give his mom a back rub. Sexual? NOOOOOO. So, don't assume affection or something like an ankle massage is anything wrong or bad. Do you have kids? If they touch you or hold your hand or sit close to you---- do you feel sexual? It is also not helpful to view your partner's child as this kind of threat. That will ultimately make for a break in your relationship if you find things like this bothersome and view her in such a negative way. Hope it all works out!! good luck
When kids can bare to touch their parent in a loving supportive way, a foot back massage, a bear hug, that indicates they DO have a healthy relationship. All good parents should have kids that care that much. You can't throw the baby out with the bath water. You can't say that there should be no physical touch between parent and child, because sexual abuse exists.
Yes, it's normal. Why shouldn't it be? I'm the same age and I give my father backrubs and footrubs. There's nothing sexual about that at all, and I'm honestly confused by your assumption that there is.