Can you pick her up and look her over. Usually I would say that she’s getting fed by the parents so don’t worry but it sounds like something else could be wrong. She’s either not quite ready to fly or something’s wrong.
Don’t give birds water. Here’s a copy and paste why. “Mothers do not feed baby birds water because their airway is on their tongue and they can not close it when you drop water into their mouths. This means you drown them, if they dont die right away they develop pneumonia and decline quickly without antibiotics.”
You have to pry the babies mouth open in the corners to get them to open to feed mealworms. Sometimes you can lightly squeeze that area but I use the tip of tweezers and lightly put it in the corner.
You can dip the mealworm in water or better yet, Pedialyte. I can give you a homemade recipe.
But if something is wrong the baby will need a rehabber.