What is this bump on my dogs snout?

No one, including a vet, can diagnose/treat your dog without examining it, least of all YA, take it to a vet.

It is not infected by the looks of it but I would have a Vet check it out the next time you have a reason to go to the Vets. It does look suspicious, possibly cancerous, a Vet needs to look at it. If it grows or changes colors take her in to see the Vet.

My dog has a spot just like that, but it's really nothing serious. However, don't listen to some girl on the internet. I'm not a dog expert, so I may be wrong. You should still have a vet look at it, just in case.

I would have that looked at by the vet, fingers crossed she has just bumped it.