Make sure that how you’re riding isn’t urging her forward. If you’ve recently been riding a really lazy horse and you’re used to keeping your leg on, it’ll be hard on the beginning. Try half seat too! Just keep calm
Well I don't know what you're looking for or your level of riding but she should fit your riding level mostly. Age, experience, size(doesn't really matter, history of its past, and health are things that I look for in a new horse. Bring your trainer with you when your trying her too.