L.E.
My thoughts are to let her sleep. She will be hungry anyway when she wakes up, the jello water will digest fairly quickly, and then she may not get back to sleep for a while which then will make her hungry AND very tired and grumpy. Plus you will get no sleep which will make you more stressed, which she will feel that something isn't right with mommy which will make her more upset. Just get a good sleep, I'd rather deal only with the hunger than everything else being intensified because of lack of sleep.