BM problem

Rachmarie23

I have a friend that I have known since I was 6 years old.  Now 20 years later I am getting married.  It was always sort of assumed that she would be in my wedding, and I asked her to be in it.  Problem is I am regretting it now.  She has a bit of social anxiety, and despite the fact that we've known one another for 20 years, she refuses to call or text unless I initiate contact.  That being said, it feels like the relationship is pretty one sided.  She also doesn't think she will ever get married, so she has said that she is living vicariously through me in regards to the wedding.  

Last weekend my parents had a engagement bbq for me and my fiance where this girl attended.  I felt like I had to coddle her because she kept wondering off on her own, not participating, etc.  Basically I felt like I was babysitting until one of our mutual friends got there so she could take over.  We do have this long history, but I don't feel like we have an adult relationship since the effort is so one sided.  

The other thing that bothers me is that my grandma recently passed away. After not hearing anything from this girl for 6 weeks (when she is never busy), I told her that she died, and she was like "oh yeah someone told me about that a month ago."  And that was it.  No condolences, nothing. 

On top of all of this, there are problems with her mother.  She feels entitled to come to the wedding due to the fact that I've been her daughter's friend for 20 years.  As such, she has told my friend that she will be an "and guest" if she doesn't receive her own invitation.  I know that she would just show up, because she did so a few years ago at another wedding.  It wouldn't be so bad, but her mother makes me feel really uncomfortable, and is not close to anyone else that would be invited.

How do you suggest I deal with this situation?  Should I suck it up and keep the friend as a BM or should I share my frustrations?  I'm at a point where I want to have relationships with people who are mature and are willing to put in effort.  Is that too much to ask?