Is my kitten a Maine Coon?

I know that rescued kittens are often not pure bred, but I'm not so sure about mine. She was taken away from her owner after she was attacked by dogs and her injuries weren't being cared for. She ended up at a rescue and we adopted her at six months after three surgeries. She has long hair with the small mane around her neck, very long tufts of fur coming out of her ears, long fur on the bottom of her paws, a long bushy tail, a trilly high pitched meow that betrays her size, she is large for her age, she knows how to play fetch, begs for food, an "m" on her forehead, wide spaced ears, a long body that she loves to d across our laps... every thing I've read online about Maine Coons seems to match. But obviously we can't contact the old owner as he's probably not happy about having his kitten confied. Any experts out there want to weight in?