My Nieces Parents are in and out of Jail and on drugs what should I do??

I have 2 nieces. A 2yr old and a 2mo old Both parents have been convicted of felonys. The father has a felony gun charge, possesion, selling drugs. And the mother has a felony theft charge. On easter they moved in with me. 2 days later it came to light that the mother got a script from a dr for tramadol (not sure on spelling) and it was for 30 pills, she added a zero and the pharmacy filled it for 300. We knew she had this problem because she tried to kill the baby by ODing when she was 5mo preg She is also addicted to Weed. Then Tues we found out she stole $1400 in jewelry from my sister (which we got the earrings back) and the very next day she addmitted to stealing my 73 yr old g-ma wedding ring. We have a case pending against her on this. But the 2yr old hates the gma on the mother side and she is also a know drug user. SRS childwellfare is not stepping in and I am scared for the kids. I have no record and have never taken any drugs and only see a dr. about 1 a yr. What do I do?