cat biscuits and bread and milk
Stop the bread and milk straight away, go and buy some purpose made ferret food from a good pet shop ie James Wellbeloved or Chudleys (Just a couple of names I can think of but there are more) theose ferret foods have all of the nutrients that are required for your jill. You should never give her bread and milk - it will just give her diarrhoea.
cheers for that get some in morning