I think Bloom is in season 7 19 years old. Cause in the beginning you had 3 years. She was 16 in season 1, 17 in 2, 18 in 3. In season 5 she gets 19, that explains the autumn-theme in season 4, Christmas in season 5 (Bloom has her birthday in December), the spring theme in season 6 and the girls with the Mini-world returning summer.