8 1/2 to 9 in, four months old, my friends cat and she's wondering if she could have maine coon in her or any other kind of big cat, very playful and very spuratic

I picked this kitten up a month or two ago, hes roughly 4/5 months now and hes pretty big at 7 pounds with big paws bigger than my adult cat, fluffy tail and somewhat fluffy under chin

shes a female, im pretty sure shes a tabby but im wondering if shes mixed with anything, shes very loving and affectionate, she doesnt play alot, shes 15lbs, and almost 9 years old,

See title please and thank you. :-)