How well do you know you're groomer? If you think she will be OK, I'd go get some things done. But if you feel you want to stay I'd stay. When we were in San Diego we had a great groomer, she never put Princess in a crate to wait, she got her in and out. I really don't see why some groomers have them for over three hours. Princess really needs to go but we just moved to NC and I have no idea where to take her. But I am looking.(I'm just very picky when it comes to Princess).
Please try not to be nervous (I know easy to say, hard to do) but you don't want Ruby to feel you are nervous, because then she will be too.
Don't for get your after groomers treat.
Hope you have a wonderful day!