Does this bird really need help? Baby birds that have all their feathers are fledglings and are ready to leave the nest. They need to be on the ground a day or two as they learn to fly, their parents are taking care of them. Unfeathered babies can be returned to the nest, for it is not true that if you touch a baby bird the parents will abandon it. If the nest has been destroyed, you can make a new one using something such as a parrot nest box and wire; nail it close to where the original one was. You should put fully feathered babies in a bush or on a tree limb, and they should be just fine. You might want to ask any cat owning neighbors to keep the cats in for a day or two to give the baby birds a chance to learn how to fly. The exception to this would be if there is an injury or the baby has been in a cat’s or dog’s mouth, even if you don’t see any marks on it. Cats and dogs have a bacteria that can be fatal to baby birds if they are not treated with antibiotics. These birds need to be taken to a wildlife rehabber or veterinarian right away.
Now what? You need to learn baby starling care such as how to keep a nestling warm, what type of formula to feed it, how to handfeed it and how often to do so. This page will assist you in helping your baby starling thrive. Baby starlings and House Sparrows require the same care and food.
Source Note: This link has a message board where other people in your situation have posted information.
So, it really depends upon its age. If it is too young to feed itself, it’s a hefty time commitment in feeding it. I would think that if it is kept in a box or a cage, it might be missing out on the opportunity to attempt to fly. If you have a screen or glass porch that your mom allows it to roam in, the two of you are committed to feeding it properly, and it’s just about ready to fly, I say do it. Otherwise, as @creative1 mentions, check into wildlife rescue centers in your area. They have the staff, facilities and experience to save your little birdie.