Chinny Babies

Hi my chinny has just had babies, wasn't expecting this as was told she was a HE! not sure what to do with babies, mum seems to be looking after them well, I have left her to it, I weighed them today and they were approx. 2oz's in weight is this ok for 3 days old? I have 3 adult chins already and im hoping to keep the babies but am I a little worried as these are the first babies we have had