The idiom mishap doesn't slip by Rey, but she's not pedantic enough to correct Elleru on it at the moment. Now that she's not 'just an animal', it's a wonder that she even knows any phrases like that at all.

"Right," Rey says more to herself than to Elleru. "Why not. Unless you're able to reach that far back, you're going to have a hard time fixing yourself, anyway."

Judging by the creature's proud posturing, pointing out the short arms in any blunt terms might not help. Best to keep that to herself.

For now.