Is this a joke?
If in case it's not then the first thing to do is to get the guinea pigs to a good exotic vet immediately. I'm not convinced your first vet is good at all. If you need help finding one then let us know where you are and we'll see if we can recommend someone.
2nd - make certain the 2 adult
GPs are the same sex. If they aren't they will breed immediately and you will have another pregnancy. If you aren't certain if they are the same sex or not then separate them immediately and take them all to a good vet to be sexed.
3rd - take the baby off the milk now. It never needed the milk. Insure it has access to pellets (without seeds or colored bits), hay and fresh veggies.
http://www.guineapigcages.com/forum/...arts-info.html
Read these links
http://www.guinealynx.info/breeding.html http://www.guinealynx.info/sexing.html Dangers of housing Guinea Pigs with Rabbits and other species
GP sick after being housed with rabbit GP severely maimed by rabbit Rabbits in Petstore terrorizing a Guinea Pig. GP kept from Eating and Drinking by Rabbits Guinea pig killed by rabbit