Fruit Trees

We have a plum tree in our yard. Who knew? Last year a late frost knocked all of the blooms off, so we didn't see any plums. This year there are plums galore. My youngest son and I went out and picked the ripe ones that we could reach Saturday. There were many others higher, and many others very nearly ripe. This morning our neighbor across the street called before I left for work and asked if she could pick the plums for jelly, so I told her yes. The ground below the tree was already covered with plums, I mean covered, so I figured before I could get out there again to pick them they would have fallen. They are so sweet and juicy. I'll attach a picture here later.
We also have a peach tree, but it is very young. It has probably 40 or so peaches on it, but they stopped getting bigger a few weeks ago. They are probably 1/3 of what their mature size should be, but I think there are too many for such a young tree. My dad told me in early spring when there were just blooms that I would probably have to pick a lot of them off. I thought he meant because the limbs wouldn't be able to bear the weight, and they probably wouldn't, but maybe he meant so the few we leave could mature. I think when I get a chance I'll pick 25 or so of them off of there, and hope it isn't too late.