Question

I just purchased 3 baby goats. One seems to be very sunken in the belly area. The other two are grazing. this one seems to follow them but see her grazing very little. I am now feeding a high protein supplement that looks like milk when mixed with water as per instruction. The seller said make sure that this one eats and I have the pellets and cracked corn but they are not interested in it. the one I am feeding still has the embilical cord hanging and is not fully dried. I was told she was two weeks younger than the other two. I hope I am doing right. She will be put in the pen with the others at night. Also, silly question when do the get the upper font teeth. this is all new to me but I have feed and raised dogs and birds from new birth and hatchings. any help will be appreciated.
Marj