If you see a kid at the vulva, it should be out within a few pushes. There should be noticeable progress with each push. If there's no progress when the doe is that far into labor, it means the kid is stuck in the birth canal and you need to help right away. If it's a breech kid, it is especially important to assist quickly because once the kid moves into the birth canal, the umbilical cord gets pinched off in the passageway and the kid can suffocate.
If you find a breech, reach in and unfold both hind legs and pull them out carefully. Once you have both hind legs, quickly pull the kid out and down, then make sure to clear its nostrils quickly. Sometimes breech kids inhale birthing fluid so you may need to clear their lungs with a snot suction bulb or a large syringe. Or if you don't have one, hold them up by the hind legs, supporting the chest with your other hand, and gently swing them with the head pointing down. Breech kids are not too uncommon, especially with triple births. If it's a small baby the doe can often deliver it on her own, but breech kids definitely have a much lower chance of survival so assistance is very important.
All this birthing stuff can be intimidating, but it's also very rewarding. Hopefully your next kidding goes very smoothly.