As mentioned, names aren't needed unless it is a franchise character an audience knows E.G. James Bond.
It would seem to me the goal is to get from A to B, which means you have a road trip movie, which is could because you'll have heaps to research to get the style pacing etc, but the why isn't defined.
Ok, so they are desperate and that gives the motivation, but the story needs something. You say they are a twin, but that doesn't seem to play into the logline, is she mistaken for her sister if not they don't need to be a twin.
Needs some stakes, maybe a body in the boot, her sister is wanted by drug lords, what is the conflict in act 2?