Abandoned and drowning baby moorhen help needed

Hi there

We had a nest of moorhens in our duck pond. On Friday, we found one of the babies almost drowned and so fished it out. After putting it in our incubator, it was back to being fluffy and perky. We had hoped that we would be able to then place it back in the pond with its family, but we haven't been able to sight any of the family and so we don't want to just let it back out if there is nobody left. Is there anything we can do to help it readjust to living outside? I will also post this in the wildlife area to widen out my chances of anybody knowing about these things.