If it's infected that bad you should have her seen by your vet, who would probably want to put her on antibiotics to help clear up the infection.
Is the infected dew claw on a front foot or a back foot? It's quite common to remove rear dew claws, especially when the pup is already put out for spay/neuter surgery. The rear dews are often not well attached to the leg and sometimes tend to flap around a bit and can get caught on things more easily. Front dew claws however are usually well attached and are a functioning toe/claw. Their purpose is to help stabilize the dog during fast stopping and turning (i.e. agility, disc, flyball etc.) Removing the front dew claws removes that stabilization and can lead to a higher risk of sprains in a dog that is active in those type of sports. There are some people who do have reasons for removing them (i.e. sled dogs often have them taken off so that booties don't chafe where the straps would put pressure on those claws, but sled dogs travel in a straight line, no skidding around so they're less at risk for spraining other toes). If you're thinking about having the front dew claws removed you should first consider what you're going to be doing with your dog and talk it over with your vet.
Beware of Mushers...They will suck you into their addiction!
If your dog thinks you're the best, don't seek a second opinion!