Maybe tell her you miss her and want to see her. She may be so caught up in the other stuff that this doesn't occur to her.

When my mom was caught up in my sister's care over the last few years, and understandably so (sis had MS), I occasionally had to gently remind her that she had another daughter too. Very gently. She just got whirled up in the other stuff. She would NEVER do this deliberately.

Telling your mom you miss her might help, particulary if you have been strong for her. WHICH IS GOOD. Just remind her that THIS kid needs to see her mom too.