I would leave him alone when he's eating, so he knows you won't take his food. And continue to handfeed sometimes or hold the bowl for him. You could also put something extra tasty in his bowl when he's eating. Just drop it into his food and walk away. That way he knows you did not come to try and take his food. It's a good thing that you were close, he just won a treat
My dog has food agression towards other dogs, so I did all these things to ensure she did not start with people. It is natural for them to protect their food, so we need to make them feel safe that no one is going to steal the food.
She also wants to own everything she finds on the floor. So when she takes something she is not supposed to have I swap. I never take it away, I praise her for finding it, and swap with a treat or a dog toy. Now if she has something in her mouth and I say "drop it", she'll spit it out and come to me for her reward. Happy to give away anything but pigs ears
You'll probably get better advise from the more experienced people in here. But these are the advise I was given when I saw my puppie getting food aggression towards other dog. I found it best to ask how to best prevent it from developing into a problem. And it has worked, she's not bothered by people near her food.
Good luck, hope it all works out for you and charlie and your daughter!