My second DD got her two bottom teeth just before she was 3months old and the rest of her teeth came early too. I think she had 10 at 6months and has had 20 for over a year so yes I do think they all come up early when they start coming early. In our family it seems to be genetic I think early teething as all the kids in my immediate family have teeth by 5ish months. I think the average is 6-7months though so yes it is early.