The very short story leaves out some very relevant facts. For instance, does VT law allow for same-sex adoption? It probably does, which begs the question, did this "spousal partner" legally adopt her non-biological child? If she did, she's in a VERY strong legal position, a position that would likely be upheld on appeal. If she didn't, she still may have a strong position giving the VT homosexual marriage laws. I'm not familiar with VT, and I don't even know if such laws exist in VT.
But, to answer your specific question, even child protective services can't "transfer custody". That can only be done with a judge, utilizing the principles of due process. In all the states that I'm familiar, CPS may only temporarily remove a child from a parent's custody, FWIW.
It does, and she didn't.
Is this the case where the little girl was very uncomfortable visiting Jenkins because she was pushing lesbo stuff on her?
Since they were joined in a civil union, the law may look on it the same way as a child born to a married woman—the father is assumed to be the husband unless other legal challenges are made.
She may have a chance if she moves where a state where such civil unions aren’t recognized, Virginia seems willing to recognize Vermont law. Other states may not be so cooperative.
No the partner did not adopt this child and the story also leaves out that the birth Mother did abide by the visitation order until her child started comign home and having nightmares and stories of her other Mom bathing with her. When she couldn’t get the court to stop the visitation she fled with her child I assume to protect her from abuse.