We have a flowering plant in the backyard that we noticed was attracting butterflies, and there were several caterpillars on the branches of the tree. The butterflies are beautiful orange monarchs, and the caterpillars are striped and very distinct looking. I found the bush online, and it's called butterfly milkweed and does indeed attract and feed monarch caterpillars and butterflies.
We came home from school one day last week and saw a butterfly stuck on the front path, not really able to move. She obviously had something really wrong with her wing or a leg but of course I am no expert in butterflies and when Ella started yelling "WE HAVE TO HELP HER! WE HAVE TO HELP HER!" I really didn't have any ideas of what we should be doing. But, Ella wasn't going to be dissuaded so I told her that we could transport the butterfly around the back of the house, to the butterfly bush, and maybe that would help her health.
It was clear the butterfly was trying really hard and she started flapping her wings and being able to fly a few inches, then a few feet at time. Ella was really gentle and kept delicately picking her up and then when she'd start flying she'd squeal loudly about how much she was helping her and how much the butterfly liked her. We made it halfway around the side of the house and the butterfly took off - she flew straight up and landed on a tree branch. Ella was so excited that she had "saved" her :)