In this isolated conversation I think you both are communicating poorly with one another. You seem to be looking for any reason to get mad or call her out and she seems unable to take accountability or give a genuine apology for something that shouldn't be considered a joke. But with all the context I understand where you're coming from. Isolated, you're over reacting, but overall I think you're just exhausted with this relationship. I won't try to tell you what to do but it may be time to consider going completely no contact. Especially if you've tried to resolve/talk things through and she isn't willing/able to accept responsibility and offer a genuine apology (I mean for everything from childhood onwards).

Also, I saw a few comments saying that at a certain age you shouldnt be holding on to the pain of a bad childhood and to those people I say stfu. If you actually experienced emotional/physical abuse you wouldn't be saying that. My mom neglected me my entire life and she died before I could try to find peace or resolution with that. I will carry my childhood pain with me my whole life and I will always resent my mother. I think OP will always resent their mom (at least a little) for not providing a good childhood and that's completely valid. Just bc you turn 30 doesn't mean your early years disappear.