My daughter has a very similar hemangioma to what you described at first. It was on her upper lip and on the skin between her lip and nose. She was oral steroids for most of her first year and then had surgery (to repair where she had an ulceration on her lip) and then laser for the discoloration under her nose. BUT, through all that, her hemangioma was going through the course of natural involution, fading more and more over time with no swelling at all. The only discoloration left has been a slight redness. I'll send you some pictures to look at if you are curious.
So, I would have a hunch too that maybe something else might be going on but it's hard to tell without seeing pictures. Do you have any to share? I know you saw the other post about the arm hemangioma that had a venous malformation underneath....maybe it's something similar??? I don't know. Or maybe it's still soon (she's only 2 1/2) and things are still calming down from the surgery and laser??
Could you go back for an appt. at Cincinnati Childrens to share your concerns? I would try to take some pictures if you can of what you are noticing. If they are the ones who have been treating her, I would say that is definitely the best place to start first because they may have someone who specializes in those types of birthmarks. I hope you are able to find out some more information.
OR- I was just thinking, since that other thread mentioned that Dr. Rosen had diagnosed her daugther's hemangioma/venous malformation, you could always email him as well. He is on the "Ask the Expert" Panel here. That might be a good lead for you as well!
Good luck! Stay in touch!