I can not tell you what you should do but I can tell you what I would do. I would write her back and in a non confrontational or attacking way I would explain what she has done with the flirting and how it makes you honestly feel. I would tell her how you feel about bringing her around you new fella. She might be angry at first and even deny everything which is to be expected. But perhaps hearing the honest truth about her behavior will change her for the better in the future or at least offer her some insight into why so many people seem to be abandoning her. We can't fix problems we don't know exsist and some people thing we can which just isn't fair. Your friend may not see her flirting for what it is or the damage it causes.

If you want her out of your life you have every right to make that choice and can even tell her the continued texts are harassment at this point and you wish to have no contact with her. If she continues to contact you, you can search out legal help. I hope it doesn't escalate to this though. (((Hugs)))