Pop it?
LOL At least I'd be tempted to, then wash the area well or apply polysporin.
And yes, my dogs hate me sometimes.
It looks like a pimple, so likely an infected bite or something like that. Or who knows, something in her system that's coming out her skin there (like an infection).
If you don't want to pop it, apply a hot compress and keep the area clean and keep an eye on things, if it gets worse or anything bring her to the vet.