I would stay away from the Sony powershot, the rest are almost equal in capabilty. The Rebel T3 you can swap lenses on so it could be more flexible overall, but you picked good models and can't really go wrong with any of the top 3. I'd lean towards the Rebel myself.
Hm. They probaly wouldent buy lenses or anything like that.
How does this the cannon PowerShot SX50 do vs the 2 nikons
I know the one nikon is 18mp the other is 16 and the cannon is only 12.
what would give them the best clear pictures and stuff
The pixel count is not much of an issue these days, the main quality differential should really be quality of the lens and the electronics capturing and saving the image. The megapixel count is great for marketing but is absolutely not a sign of a good quality picture. As I said, the top picks would all have at least very good quality pics, but since they are all about the same size, I'd go with the Canon Rebel.