Will these baby doves be okay???

There were two baby doves living in a sign above my workplace. They came this morning to move the sign to another location. I was worried about the baby birds, but they said that the two babies and the mother flew away. Well, their nest is obviously gone. Now one of the little doves is just sitting all along on a window ledge outside. I was wondering if anyone knew......will the mother come back for it? Do you think that since they are old enough to fly, they will be okay? I know most people could care less, but I worry about their well being. Poor little birds. :( Any knowledge that you could share would be very appreciated! And for those who think it is witty and clever to make comments about harming animals, please don't bother answering at all!