Should I reach out to my mother or not?

This post will be long, so pardon me for the read. The actual question is short, but the background information is what is making me pause in my decision making.

Background: So a lot has gone on in the past six months, ultimately ending with my parents getting a divorce. Since it started (and part of the reason the divorce is happening) my mother has essentially cut herself off from her family. I understand her not wanting to speak with my father, but she has in a way extended the silent treatment to everyone else at least in her family life. She has not called her parents, doesn’t talk to her aunts or cousins, and I haven’t spoken to her in weeks. She refuses to tell anyone who specifically she is staying with, or even where. She only told us the general city area she is in. Every time that we have spoken, it has been because I called her and not the other way around. Even then, our conversations have never gone over 5 minutes as she always says she is so busy and doesn’t have time to talk. Apparently she works 12 hour days every day (even though she supposedly only has a part time job) and that’s why she says she never really has time to talk. Our few conversations while short, have been relatively regular and pleasant but never about anything important. The only person she actually calls and on a consistent basis is my little brother, who is in college and has kind of always been a momma’s boy. However, her lack of communication with everyone else is not his fault so I hold nothing against him. Essentially, she’s living a life we don’t know about.

At this point I had decided to let her do her own thing, she’s grown and eventually when she wants to come around she’ll come around. I was sick of being the one to always have to chase her, while she’s being inconsiderate of how any of the rest of us feel. But the issue is, I am in the middle of planning my wedding; a wedding that she has not ONCE asked about or as offered to help with. While everyone else in my family has donated money, lended support, or has just asked how everything was going, she seems not to really care.

While I don’t really need her help with planning, I am at the stage where I am ready to start looking for “the dress”. I feel like this is really important, and normally is something that involves close women in the family, the mother, and my best friend. However, I haven’t been talking to her and she doesn’t seem to care…..I really want her to be there but at the same time I feel like I’m being petty for not wanting to say anything to her about it or ask her to come. This is a big deal to me and I’m hurt that she hasn’t even asked to be involved. I feel like it’s her job as a mother to you know, BE a mother and offer to help me look for dresses. I’m not sure what to do and wanted some opinions on if I should ask, or if I should just go with my grandmother, aunt, and BFF.