Young pigeon stranded on roof

I feed pigeons around the area where I live. Next door to my building there's a tree and a pigeon has a nest there. The baby pigeon had been doing well. I could see it from my balcony. Today I noticed that it was on the roof of the house beneath the tree. It might have flown there because it's not a baby anymore - but it's still young. I noticed a couple of adult pigeons spending time next to it but when night came the adults flew into the tree leaving the younger pigeon on the roof. The little bird moved over to the very edge of the roof closest to the tree but didn't try to fly over to it. She settled down for the evening on the roof. Question I have for you all is - do you think I should watch this situation and see if the adults feed the younger pigeon or if she manages to fly rather than go try to take her from the roof? I'm not an expert on baby pigeons so I'm not sure how close this one may be to the stage when they begin flying. I threw some of the pigeon seed mix on the roof so the youngster would have access to it but she didn't seem interested. I'm not sure if her parents are still feeding her. There's a section of the roof that has shade and I could continue to throw bird seeds over there but water is an issue. If she does belong to the adults - will they continue to feed her even if she isn't near their nest anymore? Any help would be appreciated. I successfully rehabilitated an adult pigeon who was sick last month but babies I have no experience with.