I [30M] don’t think I really know who my fiance [29F] is anymore. Not sure what I should do?

I , 30M, have been with my fiance , 29F, for 12 years and we have a 9 year old daughter. We have had plenty of good and bad times and have been through a lot. Started dating when I was 17 and she was 16 and now engaged for a year. But lately I have really been noticing just how inconsiderate and kind of childish she really is. It used to be little things like leaving her shopping cart in parking spaces at grocery stores even when the cart rack would be right next to her, just not really considering others points of view at all. Working with her I’ve realized just how much she will take advantage of our coworkers to do her tasks for her. And in general a lot of little things that just really shows that thinks very little of not at all for others around her.

This week though her little brother, 20, and his girlfriend, 20, have been staying with us and it’s become almost embarrassing just how childish she seems to be. We had to get a rabies vaccine for our daughter today who was bit by a stray cat yesterday, just out of precaution. Her brother and his girlfriend were with us in the waiting room. And one other man that looked like he had some issues and was over weight walked in. They were all already acting up and being very loud and obnoxious with her brother actually dancing and walking around the waiting room. But the other man sits down and they proceed to giggle and pull out their phones taking pictures of her little brother with the man in the background. It was very embarrassing to see and hear my 28 year old fiance to giggle and snicker and snap photos in a hospital waiting room, to me it felt extremely rude and awkward. There is a lot more to it but I’m not the best writer and there’s a lot of details in between and over the years. She’s not always like this and being around her siblings makes her really act differently from what I usually see but today has really confused me on who it is I think im engaged to. I don’t want my daughter being shown that making fun of and talking about others for laughs is ok at all ever much less in public or a hospital at that.

Does it seem like teasing others in public and basically behaving like a middle schooler at 28 is kind of weird? Would you have a problem being with a person like this?

TLDR; my fiance has been showing how inconsiderate she really is for others lately.