1. Looks like chickweed. Safe
2. A young horseweed perhaps. This one tends to be debatable on its safeness. My opinion is that if it's growing in the outdoor enclosure and the tort eats it then it's no big deal. But it's not one that I will purposely offer.
3. Buttercup. Considered to be toxic if large amounts are ingested. I despise this invasive weed. http://www.thetortoisetable.org.uk/plant-database/viewplants/?plant=71&c=6#.WsKPU-BlA0M