I'm curious what grade are they in, or how old

At first I thought they were at least juniors, or in the 11th grade. But then came the Halloween episode, where they wanted to go trick or treating , showing some immaturity, so now I thought maybe they're only sophomores or freshman.

But then poses another question, I can't believe that a highschool would consider freshmen to be popular like Casey was and Molly and Grace are still.

I really don't see the Seniors agreeing that a freshman girl be the most popular kid in school like Molly.

Does anyone else see how this is strange.

I know it's a sitcom, but still.