I admit I have very high standards for who my partner will be (if I ever decide to find one), and one of them would be her willingness to let me spend time with her AND her friends. I'd likely share quite much in common with her due to my standards, and because of that I would likely prefer to spend time hanging out with her and, as I said, her friends as well. Is that normal?
I think it's normal to want this kind of relationship. Some people find it stifling, but some people enjoy the extreme closeness it can provide. The trick is to find someone who is looking for the same amount of involvement in her partner's live. Although, don't be too picky, otherwise you might stay single forever! ;)
this sounds completely normal, and in fact something in which I find fascinating, because its like connecting the dots...
if you have something in common with someone, and do get along with her friends, its not illogical or 'not normal' to spend time with her and her friends, but its seems you already know this~