A.C.
You might focus more on "taking turns." Whoever has the toy is currently taking the turn, and after that child is done, the other kid gets to play with it. If needed, especially for the 2yo, you could set a timer so he knows when it's his turn.
If the 2yo is taking toys away from your daugther, he needs to be corrected and/or distracted--he is the one that is doing something wrong (although he doesn't really get it that it's wrong, probably).
Putting toys that are particular favorites into "timeout" can be effective, if they are both at fault, or if it's just too much for the 2yo and he can't deal with it.
Or, if he's being really bad about it, putting him in timeout can also help (if you have a pack n play, you try that to safely contain him).
Unfortunately, this is not something that will get fixed overnight--it takes a long time to learn the concept of sharing. And kids don't really play together interactively at this age (they can do something called "parallel play" where they play nicely next to each, but don't really interact in the sense of "lets play cars and we'll build a road together" kind of thing for quite a while).