I think Kingston has a MacDonalds.
Never eaten here but we have stayed very close by and have walked along past this restaurant. Pretty easy to find at Boulter's lock, Maidenhead (near Maidenhead bridge):
Boulters Restaurant Bar - Maidenhead | Restaurants in Maidenhead
Hidden behind the restaurant is a small island with squirrels and a few small animals in cages (birds, guinea pigs) and a close view of the fast-flowing weir just behind the lock. We took the kids there and got ice creams on the island too.
And downstream there's the picturesque bridge and rowing club; a nice walk IMHO.
French Horn at Sonning