First of all, physically separate them when you feed them before the puppy gets hurt. Second put things like treats and maybe even toys away to where there can be no fighting over them. Put things like that in a confined place with one or the other. I've never tried feeding dogs with both loose in a single room, so can't tell you any way to "fix" it, but before others here chime in with advice, and you start to act on it, "fix" things so the puppy doesn't get hurt. Dog to human aggression is a different things from dog to dog aggression. The older dog humping the younger is her asserting dominance over him. She's worried about the puppy. Don't give her a chance to do anything injurious about it.