They can lose their first tooth any time from about 4 to 7 yrs, my DD1 was 5 and DD 2 was 6. My brother lost his first tooth at 7 1/2. the peak age seems about 6, my yr 1 class lose a lot of teeth LOL. DD lsot her 2 front teeth at the end of last year and it has taken 6 months to even get one new one grown! She hasn't been able to eat apples or corn on the cob since October LOL