how to deal with misgendering and for the future….

pretty much as the title says, im pre- T but i pass pretty well for my age. when i go out i pretty much get gendered right and i could correct people on it, but my issue is just the constant shes and hers i get from my mother as she’s talking about me. and i’ve avoided that stuff by just not being in the room as she is but this time i was part of the conversation. anyway, ik im asking for advice but please no “why dont you tell her to stop/use the correct pronouns” as she cant seem to understand shit nor does she want to really, or “do something to distract yourself from it” because i already do. im just concerned for when i start Testosterone, in like 29 days, and have been on for a while… would she still call me she? And if any one of you guys here have been on testosterone for a while or enough to make a big difference and your parent(s) still call you a girl, how do you cope? or is the ultimate solution to all this, to just not give a fuck? cause im halfway there.