Well speaking as a mother myself, I do find it tiresome to reguarly be approached in the chatroom with messages like "Do you tickle your kids?" or "a ticklish mom, huh?" I have seriously considered taking that little tid bit out of my profile, because it really has nothing to do with my ticklishness or my kink lol (I suppose I had it I there for a point of reference, like hey this woman is a wife, mom and professional, she has no time to meet up with you)
That being said, I am okay with mother/daughter and mother/son tickling in fiction. While it is not really my thing, I have read plenty of erotic fiction over the years that I would not approve of in real life. I think a lot of people have all kinds of different social dynamics that make them tick, and as long as it is explored in a safe way (such as a fictional story) then I think it is probably okay.