as long as you are right there to supervise and make sure things don't get too intense, you'll be fine. i'd let them play together but when you're busy with other stuff and can't be right there to watch them, keep them separated.

can you stop your terrier with certain commands when you think she's getting too rough? have fun!!

I agree. Take them for a good 45 minute leash walk every morning afternoon and evening to wear them out a bit then maybe they wont be so rough with each other, although there is no guarantee. When my pup was younger he and another dog the same size were playing, she was a greyhound dobie mix and liked to twirl, She was twirling bumped up against my pup and snapped her ankle bone in half which had to be surgically pinned....poor thing. The whole thing happened in seconds.