My daughter who is a preemie is 15 months with only 2 of the bottom primary teeth, those same teeth started showing after 12 months, should i be concerned?

Late, but OK: It is normal for children who are born premature to get their teeth late. There is no hard fast rule. The important thing is that she "keeps up with herself" and that the teeth continue to erupt in the normal order. To allay your concerns and to keep her future teeth healthy it would be ideal to have her seen by a Pediatric Dentist who can monitor here progress.

Not concerned: Not concerned, but curious. Important that you have your child examined by a Pedodontist, a pediatric dental specialist, who is best trained to evaluate your daughter's dent-facial development. Your question is best answered by this type of specialist rather than a generalist. At 15 months she's 3 months past due for her first dental examination anyway. So please call a Pedodontist.