Yes, any girl can play football! There are no rules (in any form of American football) that prevents girls from playing football. It is very uncommon for girls to play football however, mainly due to the peak physical attributes required to play the sport. There have been females involved in football, but usually only in the high school or pee-wee level. There are also female-only football leagues. So although it is stereotypical for the sport to be only for men, women are permitted to play, too.
In fact, many female football players serve a very specific purpose. They are often kickers on the special teams unit. This is a position where size is not important. In fact, many female kickers have a lot of soccer experience, which is why they especially excel in these roles.
DID YOU KNOW: In 2018, Rebecca "Becca" Longo was one of the first female players to be awarded a partial scholarship for football at Adams State University in Colorado. The longest field goal she's kicked was a 54-yarder during a practice last year.