TS:
In this type of scenario, you would need the help of a mature adult.

Have a thorough talk with her with another friend ( preferbly a much older person )
First thing, ask her what does she really wants by doing all those nonsense.
If you dun like her, tell her in a very harsh way. Say that the things she is doing, is degrading herself n ruining her reputation and alot of people around her sees her as a nuisense. With her loud talking and touchy way, whats the difference between her and the prostitue from geylang. You will need to be very persistant and very harsh when saying all that.
Wake some sense into her in a very serious and very harsh way. If you can't find yourself bear to do it. I dun mind providing the service. This type of person needs to wake up her mind before she dig deeper into the grave and ruin herself in future.
If it still dun work, just ask another gal to give a her a tight slap on the face to wake up her mind ( if you dun wanna use your own hand ).
She will need to get into real deep sh1t once before she will realise what she has been doing is a nonsense.
If all these doesn't work, use the ignore button. Ignore her completely and thoroughly.
Cheers
From old man