Where should adoption take place???

Hello all, I have posted here a few times in the past and found that there are some very helpful people here. I am very thankful for that. I am back now with a new question. My husband and I recently took in our great-niece. She is an absolute joy and I can not imagine life with out her. We have full legal custody of her. Our next step is adoption. So here is my question......we live in West Virginia, however we had to go through the Ohio court system to get custody ( that is where our great_niece was). So in which state should I file for the adoption? Thanks to any and all who can give some advice.