My friend has relapsed...

I’ve posted about her before, she is technically senior to me at our workplace. For the past six months she has managed to keep her performance up, but the last few months things have been falling apart. I think a few of us have covered for her including myself...
She went on a bender yesterday and missed her family Christmas. She video called me tonight sobbing and saying she knew I had to report her. The lines are getting murky now and I don’t know how much longer I can have her back. But we are friends first. I just hope she goes through with her rehab plans. I guess I will have to re-evaluate on the 4th of Jan. There isn’t really any true friendship left when someone goes down the heroin rabbit hole