What is going on?

Question
My Guinea pig just had babys. But now she is loseing her hair on her neck and legs. I don't no if it is bad or good.

Answer
Hi Jody

this sounds like a hormonal thing given that your girl has just had babies.
Her body has gone through a lot of changes during pregnancy and this could be why her hair is falling out or thinning.
There is a good chance it will grow back when her body has returned to normal - this could take up to 6 months tho so please be patient.
If she shows signs of irritation tho this could be mites or something similar and will need treatment. This should not involve a trip to the vet as most conditions can be treated at home by you - I will help where I can :)