I don't know what the procedure is with your particular insurance, but just keep in mind there is always a way. If your daughter's doctors won't refer you to a Hemangioma specialist, you can request Authorization from the insurance with a letter explaining your situation, and some photos of your child (well, that's how I had to do it, because I could not get a referral either). But, I'm not insurance expert, but I thought I'd share how I got authorization.
My daughter has a large H on her head too, it's raised, looks like she bumped her head or something. I am scheduled to see Dr. Waner in May for surgery. I do not believe surgery is extreme, and babies heal very well and scar less than older kids and adults. Surgery for the excision is usually better to do when they are young, rather than years down the line. Of course, it depends on what the specialist recommends for your individual child's H.
We'd love to see photos of your baby if you are able to share.
PS - The sample appeal letter on this site helped me... maybe you could get some ideas from it for requesting Authorization from your insurance company.