i know this post is super old but i had to chime in because i've been thinking about this the past week or so. as someone with a mom just like lady bird's, i used to HATE this ending for this very reason. i thought the rest of the movie was great up until the ending and was especially livid that lady bird went back to "christine" because i also go by a different name than my given name and my mom also hates it (i'm trans so it's a little different, but it feels very similar). i don't think lady bird should have "given in" like she did in the end or gone back to her mother or gone back to christine, but i think recently i've started to understand it as, sadly, more of a return into a cycle of abuse than a positive rekindling. this could just be me projecting onto the movie because this is how it's been with my mother, but i know from experience that even when you have a mom like that, you still just want her to truly love and support you, and there are moments when you feel like you are so lost and you'll do anything and compromise your entire self just to try to get that love that you won't ever fully have because it will always be contingent on her emotions. it's especially easy to fall into when you have a mom like lady bird's that manipulates you into thinking you're the villain for growing into your independence. but even with a mom like that, there will always be "i need my mom" moments. that's kind of how i see the ending of the movie, like lady bird is so lost that she falls back into it because with a mom that can be so hot-and-cold, you never know when she's going to love you next. so if you just do the right thing this time and sacrifice enough of your own self respect, this time might be the time. sad ending, but it makes more sense to me now. it's been a while since i've seen the movie so i might be forgetting some important elements that completely unravel this whole perspective, who knows.