Can you press charges against someone that becomes adult in like 2 weeks that pressured a minor into sending nude pics?

How old is the minor, and what state is this in? There are different laws at federal and state levels regarding the possession of child pornography and coercing a minor into lewd sexual acts. Generally speaking, even if the "someone" in question is under 18, they are still in possession of child pornography, so they can be arraigned. Whether they can be charged as an adult or as a minor depends on the laws in that state.