Support in an uncertain adoption case

Hello everyone, I'm new to forums like these, but wasn't really sure where else to look considering my online searches have come up with nothing. Hoping some real world knowledge will help me out. My fiance and I are fostering her niece, who is now 2 and a half, since she was removed from her parents care upon leaving the hospital after birth, so we have had her since she was a week old. Initially, the plan was for re-unification. Oh how time changes things. Both parents have shown the inability, from DCYF's perspective among other's, to care for her. The case for TPR is currently under-way, and it looks like the TPR will go through. However, information was shared that if the mother were to appeal to Supreme court, which could be likely, then she potentially has some footing to work with based off of errors committed by DCYF. What options do I, as a foster parent, have in protecting her? There has to be some grounds, somewhere, that gives more protective rights to this little girl other than her getting placed back into parental care off of a technicality. It's mind-boggling to me that this could happen based off of an error. Now mind you, I don't care what effort it takes on my part. I will tear down mountains for this little kid if I have to in order to protect her. If anyone has any information or advice it is greatly, greatly appreciated.