12 year old female in a relationship with a 16 year old male?

I don't see a problem with it but you should introduce yourself to the parents if you want to have a relationship. Make sure as well that she is 16, and not just saying she's 16.

Four years isn't much when you are both in your 20's or older, it is now! She is still in high school and you have graduated and are likely out a couple of years. You and your friends may likely be okay with it, her parents not so much.

I'm guessing you can legally drink in Wales but I am not sure about her. Not sure if she should drink even if old enough. She and her friends will think it's great she is dating an older guy.

It might be better to date girls closer to your own age for now. In a couple of years, 18 and 22 looks okay.