What legal right does cyfd have after dismissing the case?

Can CYFD in NM force someone to care for a child that is not theirs?

My 17 year old sister made false allegations to her counselor about my parents, in the hopes that the counselor would call a meeting with my parents. My sister hoped she would be able to stay with a friend for a few days until it all blew over, because she had been grounded. My sister has a mental illness. She did not know that the counselor would have to call CYFD in. The State asked if she could stay with my bf and me, and we said yes, as long as it's not much longer than 2 weeks tops, because we cannot financially care for her. We are also in the process of moving, and this is why we are strapped for cash. CYFD won't allow my sister to go home, unless my sister says it is something she wants to do. I have called on several occasions to see if we can set up a meeting to try to get her home, where she can be properly cared for. CYFD has stated no. However, my parents ARE NOT under investigation for child abuse, so I feel like this is not legal for them to FORCE me to care for her. When I told them that we would not be able to buy the groceries she would need to eat next week, because we're a little hard for cash, I was told "Just because things are hard for you guys doesn't mean she'll be safe at home." My mom has helped with groceries already, but there's only so much we can all do on limited income. My mom still has her own home to buy food for, and can't supply my house fully. I DON'T HAVE CHILDREN for a reason, and we are BEING FORCED to care for someone else.