First off, I worry if a child hits 12-15 months and doesn’t have ANY teeth yet. So, she is well within normal limits. The times that teeth erupt can vary considerably. Here is a chart from one of my development textbooks showing the average times that various teeth erupt. Keep in mind that what is considered normal will be about 4 months before or after the average:

lower central incisor – 7 months
upper central incisor – 8 months
lower lateral incisor – 8 months
upper lateral incisor – 9 months
1st primary molar – 13 months
cuspids (canines) – 17 months
2nd primary molar – 22 months