You have to remember that anything with a PG rating can have adult situations (such as rpe, mental health, sx etc.) But you can’t be explicit about it if you get me?
So for example you can have a couple in their underwear kissing in bed but you can’t describe the sexual act (so technically they’re making out not having s*x). You can describe the emotion they feel towards each other (stuff like “when I first saw him, his eyes sparkled in the light”. Sorry for the cheesy sentence).
Or in r*pe storylines (you’d be surprised how many teen around 12+ range know about it), again you describe the emotions, you don’t describe what happened (always put a trigger warning and give an option to skip).
Same with mental health and mafia. It is possible to write about adult situations within the PG12 age range but you just have to be careful how you write it if it makes sense