I have this friend...

So I have a friend with a lot of issues. She’s with an alcoholic and she desperately wants kids but he doesn’t. Because of that, she treats my son like hers (She says he fills a void for her) - It’s not necessarily a bad thing but I’ll be right there and she acts like the parent. People in my circle don’t care for her because she has no filter and she’s a little strange and outspoken. On top of that I feel like her therapist because of all the issues she has going on. I always pay for things when we’re together and she rarely offers. I’m pregnant and have been having yeast infection issues and on Halloween she made a joke about it in front of everyone in the room! Since then I have been avoiding her. She’s called and I just don’t want to talk to her. My mom said not to cut her off completely just don’t be so close. We’ve been friends for awhile and she has helped a lot with my son while I’ve worked in the past. I feel guilty about avoiding her I’m just so over it. What do you think?? Any advice?