I know babies who have had them from 3 months and others who haven't had any until 13 months. Every baby is so different. My DD1 got her first tooth at 4 and a half months and my other two had none until they were 7 months. They have also got them all in different orders. They seem to get the middle bottom two first, but DD1 got her eye teeth, the ones either side of the middle teeth at the top, second and had a massive gap there for a while.

How exciting for your friend that her baby is teething. Little milestones like that are fun to celebrate and acknowledge