After Super Girls final fight against Galatea where she either went, into coma or dead ambiguous for you to pick Prof Hamilton unable to deal with the grief of losing a closest thing he had to a child opens up the second possible Galatea this one not age past Supergirl but physically at number of years younger then Supergirl was presently he takes her into hiding with him with the plan to raise her like an actual child. Let's go with story ideas from there