I'm most definitely a four- Not that I'm an SJW or anything, but if it's not all-inclusive you better know you're getting a strongly worded paragraph about why you should use they instead of he or she.
Mia sounds like she'd be the type of person to drive the plot- As any protag should, but I think she might lead with her heart instead of her mind.
I've been watching too much NOAHFINNCE, Jammidoger, and Sam Collins lately- so I'm ready to point out any sort of tomfoolery in that category.
I'm a little bit of a grammar cop, but if you've already got one of those I'd gladly help you out with four.