Should I not feel guilty for keeping my distance? Should I just disregard what others think of me and always be by her side? The whole situation gives me anxiety. I just don’t feel safe around her.
You should not feel guilty because this isn't on you. Your kid has to know right from wrong, and it is no longer your job to teach her that. She's entitled and unstable, plus she's old enough to make her own choices. So let her make them.
For your weekly texting, if she gets ugly or makes demands, then you need to tell her that treating you that was is not okay. If she blows up from your statement, then you wish her luck and say goodbye. That's your first boundary that you have to enforce each and every time- you love her and want to help, but you don't feel safe when she's being mean or manipulative.
One of two things will happen- your kid will change or she won't. If she doesn't change, then you end the weekly texts quickly and block her (for the week at first) when it becomes too much. In short, you hold her accountable for her own words and actions.
For the other part...about what others might think from what she's said...you have no control over that and shouldn't worry about it. She will cross those other people soon enough and they'll feel dumb for judging you.