So umm... Rogue acted like sugar baby, Jane had a "big sister" thing, are both kinda based on original comic setting? or maybe a bit exaggerated compare to comic? I kinda like these stuff tho.
Very early on in the comics, Rogue was quite rough around the edges and unladylike, but after joining the team and being around more positive influences, Rogue underwent character development and started looking after herself, becoming more of a southern belle than thug from the south.
In the comics Jean was the youngest child in her family so she never got to be the big sibling until she went to Xavier's Institute, where she became something of the den mother for the rest of the team (a den mother is a woman who plays a supportive or protective role for a particular group of people). How Jean acts in the game is something of a progression of that.
Essentially, these are slight exaggerations to the comic versions, but nothing too outrageous or utterly out of character.