For a fact would goin out wit a younger grl make d relationship childish in a way?

I'm 17 n she's bout 2 b 15 in a few days. Wen I talk 2 her idk she dosent act childish or nothing she would always txt ne Diz face :p. I'm my opinion she's having fun since she's gettin attention from n older dude. Wt do y'all think am I rite?