A Dremel is an electric mini-drill used most commonly for hobby work. There are about a hundred different drill bits and other thingies that you can used in the Dremel for your craft work. You can mount a small rotary sander in it which would work fine for trimming the dog's claws...if the dog was of a mind to cooperate.

You are wise to have the groomer do it. As you say, the dog won't blame you and this assists you in maintaining her trust. Also, dogs usually act up a lot under treatment more if their owner is present. They figure it's a good time for some emotional blackmail... ;-)