Hi and welcome to the Chiari forum
We do have a list of Drs compiled by the members who have been to, ,treated by and liked the Dr...we do not consider our list a referral nor an endorsement..It is mearly a starting point to research Drs....not all on the list may be true specialists...but do treat it...if you want a true specialist you may not find one close to home and may need to travel....
The size of herniation is not the main concern.....is if you have a CSF obstruction or other related condition/issue that needs attention. Surgery can not help everyone even if they have a Chiari DX...and having the right Dr is key!
I know off hand there is a Dr in NC and 2 up in the Baltimore , MD area...next there are Drs in NYC,,,you could head down toward Disney as there is a specialist near Orlando...depends on which Dr you prefer....see a few compare them and compare them...and of course educate yourself on Chiari and ALL related conditions to help you know when you have the right Dr.
I would suggest Children's Healthcare of Atlanta. They have neurosurgeon's that specialize in Chiari-Malformation. I am not saying that is where you should go, I am just giving you a starting point.
I know it is not a short drive and when I lived in Marietta I tried to avoid the freeway traffic in Atlanta like the plague, but that is the best I can do. I hope everything turns out great for your daughter.