My Aunt is shooting in the bathroom?

Ok my aunt is 30 and her sister (my other aunt cindy) and I know that she is doing drugs in the bathroom and lying but we don't know what to do with her. She lives with Cindy under the condition that no drugs come in her house and *annie not doing any drugs while she stays there but about 2 months ago she said she quit shooting up morphine and i think she did quit for a while but she comes to work and talks to me and takes her purse in the bathroom and stay for 20-30 minutes every time and she's been doing it at Cindy's house too and one day Cindy asked what she was doing and she said #2 and Cindy looked under the door and she was standing at the sink then Cindy went in after she was done and there was about an inch of water plugged in the sink and a paper towel with a little blood on it in the trash. Is she back on the needle? Are these signs? My whole family is over being heart broken about her but my Aunt Cindy doesn't want that around her children and if she kicks her out she'll try to come to my house and she tried to punch my mom last year so that's a no and I don't want it around my siblings because i don't want anyone else in my family being influenced by her behavior so what to do? What does Cindy tell her she can't keep using people and not try to help herself right? Oh and annie has three kids that are taken away from her and needs to grow up how can we possibly get her to? I think Cindy won't kick her out because she knows she doesn't have anywhere to go so any advice for her would be great. And I keep getting annie pissed at me for telling Cindy what she does when she's with me but I think Cindy has a right to know please what am I right or wrong about?