Awkwardness between Mel and her sister

Is it me or the actual relationship and chemistry between the two looks really forced? Now I understand they are the only families left for each other and all that. But yet, it doesn’t come across as natural. Also how normal/common is it to address your sibling as “honey” THOSE many times? I mean a casual hon or sweetie here and there I get it but they literally address each other honey all the time and it sounds very odd. Anybody else feels this way?