Take her temperature. Any other symptoms besides the snot? If you offer a bit of grain, will she eat it? How's her demeanor? Acting normal, or acting sick, head down, etc?
Just to be on the safe side, I'd take her temperature, and keep an eye on her. Has she had any stresses or changes lately? Moving, kidding, etc.?
If she wasn't vaccinated with the pasturella vaccine, my guess then would be that it's a pasturella overgrowth (shipping stress). I had this in my 2 bucks when I brought them home. All goats have some of it in their respiratory tract, and stress can make it flourish. Keep taking her temperatures to insure they stay normal. Keep an eye on her behavior. You can give benadryl to help with the symptoms. In my goats, it passed through my little herd, much like a cold (so if the girls aren't quarantined, your other goats could get it, too, even through a fence) but ran its course in about 2 weeks. Since these are new goats, if you haven't done it already, I'd also go ahead and treat for cocci and worms, even if you don't see anything on a fecal (it's winter and they can have it w/o you seeing it, and it's a good idea to do this whenever you bring new goats home). That way, you're also insuring that they aren't battling parasites along with a snotty nose. Parasites can be silently overwhelming and make it that much harder for her to fight whatever else is going on.
Looks like Billie gave you sound advice. You could help us by taking her temperature as she suggested. Make certain her eyes are bright and that she is not droopy and that she is eating eagerly.
I also along with everything else suggested is start them on Vit C and an antihistamin. But that is just me
Benadryl is the safest. Tri-Hist for equines would be my next choice. But it's just so much easier to give the benadryl. Tri-Hist is granules and if they're picky eaters...forget it. Kaye
no kidding, got a whole can of it, horse wont' touch it. i tasted it myself, and can't really blame her! my vet said its a pretty low grade, low strength product anyhow