[lucyjoy]

If you think there will be a chance mom could parent at some point in the near future, perhaps you could obtain legal guardianship for now. Legal guardianship can be overturned at a late date should mom be able to parent.
With legal guardianship, you would be able to act as the child's legal parent for all needed purposes.

The big risk here, though, is that mom could decide to be no part of the child's life at all and then 6 years later come back to claim her and she could. That isn't necessarily good for the child.

My grandson's mother didn't want to be a parent and doesn't like parenting. She does love her child but resents the demands of caring for him and though he is fed and washed and clothed, he is often emotionally neglected. She wanted to place him with family but her mother talked her out of it. I'm not sure that was the best decision.

Anyway, legal guadianship is a route to explore.