Do you know how old she is? She looks very Beagle to me, and 15 inches is a good height, but I do think there may be some other kind of hound in there, particularly if she's still growing! She is a cutie, that's 100% for sure, and constant nose to the ground is typical beagle. There's a saying amongst beagle owners - you do not walk a Beagle. The nose walks the Beagle, and the Beagle walks you!