How many hours is it between dinner and bedtime? Smaller bodies are smaller systems, so they do empty faster than an adult; that's why snacks are needed throughout the day, too. (of course, I snack too, but that's a different story)
For our son, we gave him a nightly bottle before bedtime into his 2's, and far after he was weened from the bottle for the rest of the day. This was for 3 reasons: first, to get him to sleep through the night without waking hungry; second, to supplement vitamins and protein, as he was fussy about proteins, in particular; and third with something warm to calm him.
I'm not saying that's a catch-all, but I don't think it's bad to give her string cheese as a snack before bed, on the face of it. Of course, son has also used hungry as a stalling tactic to going to bed, so we have to know when to call his bluff. And, at 3, we are past that phase, and he eats a big dinner sometime between 6-7 and goes to sleep just after 9:00 with no issues. Your child may vary, but that's what worked for us.