Keep in mind that, whatever your intention, it is not legally your decision. You could go to court and try to get a judge to override your daughter’s decision either to place her child for adoption or to parent independently, but the likelihood of that’s working is very slight.
Very few states have any grandparents rights. Even with my former daughter in law being a proven drug addict and felon who was homeless and moving in with a different drug dealer every few weeks it was a long and expensive legal process to get custody. Adoption was equally long and expensive. I would do it again tomorrow