You haven't said how old your baby is, but it is best to give her cooled boiled water to drink if she is under a year old - having said that, I think that the risk to her of drinking plain tap water before this is really small especially if she is getting close to a year old. I stopped sterilising and boiling everything when my son started drinking water out of puddles in the street and chewing on shoes - he was probably about 10 months then. It just seemed a bit pointless.He seems to have a cast iron stomach and is very rarely ill - maybe he learned to fight off germs at an early age.