Here are some local ones I found...
Doggone Groomers
A-Klass K-9 Kutters (gets you first in the yellow pages listing )
One Stop Grooming Shop
Super Groom Pet Grooming
Pet Haven Salon
Hair Apparent
Fur Styling By Tammy (insert sister's name)

Here are some non-local ones that I thought were kinda cute...
Scrub-A-Dub Doggie Inc.
Groomingdale's Pet Salon (Laura already mentioned this one, but I think it's so cute!)
Groomingtails
Clippity Doo (Mobile) Dog Spa
Doggie Doolittle's Grooming
The Pampered Pet Day Spaw
Wags to Wiskers Pet Grooming
Spot Free Dog Wash
Cruzin' For A Groomin'
A Fur Affair, Inc.
Dog Gone Hairy
Ushampooch (LOL!)
Doggie-Do & Pussycats Too
Tails A Wag'n
Pup Purri
Wag N' Wash
K-9 Hair Design
Kiss my K9
Bow Wow Bath & Barber
Bow Wow Beauty Boutique
Shear Critters
Beauty in the Beast
Paw Snikitty Pet Spa
Dunk-N-Dogs
Bill's Doggie Bath-O-Mat (insert sister's name)
Bark n' Bubbles
Kutz for Mutz
Mudpuppy's Tub & Scrub
Double Dog Dare Ya
Four Your Paws Only
Fur's A Flyin
Julian's Dog Gone Cute (insert sister's name)
Dog Gone Pretty
Doggone Good Grooming
Chow Bella
Laundramutt
Doggie Style (LOL!)

Maybe with some 'tweaking' one of these would be appropriate. Good luck to your sister in deciding on a name as well as with her new business venture!