I replied to this earlier but it was lost due to the BT problem.
Looks as if my view is the opposite of everyone else's
How many small birds do you have? How many sparrow hawks are there? I would think you can't count the number of small birds, but there is only the one sparrow hawk. This means you have a predator/prey balance, where there is room for small birds to be taken. Were she to take too many, then she would be left to starve, so nature helps to reach a balance.
We all love the pretty little birds, but the sparrow hawk is so beautiful herself. But it's not really up to us to judge a creature's worth by how cute we find it. If you are feeding birds on your feeders, then you feed all comers, including the predators (and those pesky jackdaws).
If you were to cage off the feeders, the hawk would simply wait until a bird flew out of the cage. She will also continue to hunt along hedges, by scaring the small birds into taking off, so she can catch them.
I would be proud of feeding enough small birds that your area can now support a prey species.
This morning in the big wind, a juvenile sparrow hawk landed on my garden gate post, but the wind caught it, so the tail was blown up in the air, and the bird tipped right off the post. I found it funny but I do have an evil sense of humour.