Especially since shes older I'd say break her into it very slow. If you get a plastic crate, take the top of and let her play in just the bottom then start putting the top on. If its a metal one, play fetch with her into it so she gets to run in and out without fear.
Also feed her in it and don't make a big deal when she comes out of it, but make a huge deal out of it when she goes in.I'd also so not to give in if she barks or whines. My dad always told us that children and animals are the worlds biggest terrorists and no matter what there is no negotiation because if you give in once they know you'll give in again. (may not be totally pc, but is still rather accurate)
Good luck!