Girl steps out of car and gets smacked by a truck...
...and survives?...and suffers no ill effects from it? No cuts or broken bones?
Did I miss something?
If you watch the scene closely, Aimee doesn't get run over. She's knocked aside by the truck's speed and has some kind of broken bone. If you see her in the scene in her room, she's wearing her arm in a sling. By the time she goes to college, her arm has healed. The scene in her room is implied to be a little while after the accident - after which any cuts and bruises would have healed.