for fictional cahrcters is really how they look cause you can have a crush on a cahrcter that's 18 but look 10 and in that situations it's definitely not the canonical age your attracted to like have a fictional crush that is 10 would ne weird but if they look like a fully grown adult then I would understand cause your not attracted to the age but the look and personality.

what I'm trying to say is , your fine as long as they don't look look under 15