Small town problems!

These 'sides' of yourself are all just part of you and completely normal. We are all a mixture of different interests and thats what makes us rounded and interesting. They shouldn't be 'personas', they should just be you as your consistent self doing different things in different contexts, rather than performing a set role you feel is acceptable to the group you're in.
Trying to play roles of sensible mum with this group or party girl with that is hard work, when what you should be striving for with friendships is just 'being' and being liked and accepted for who you are.
Your friend and you are two individuals and are each joining other groups as such. You and she will either fit in or you won't. If they are so very different from her type, she may well opt out anyway. However, she could surprise you and reveal she is also a muti faceted person and she could fit in better than you.

But she’s clearly trying to expand hers too!

I live in a small town too. I have a wide friendship circle abd fairly often these collide. It's really not a problem. You can be friends with other people too , she's obviously going to a meet up group to meet new people as well!

Your response is very odd and tbh and if I was the organiser I would have quietly noted you as "one of those" and probably not gone out of my way for you, especially as you have unintentionally said something negative about another member

For heaven’s sake, OP, hasn’t it occurred to you that other people are also multi- faceted, to the same extent you are? My friend who attends fetish parties is by day a well-regarded senior medic. The ex-nun friend did her fair share of shagging about on the backpacker trail before entering the convent. People are various! Not just you!

And?

Why do you think she would care that you want to meet new people, when you've said she loves meeting new people?

She'll likely be very happy you both want to meet new people!

Sorry but not the same at all - i wouldnt not go to an event because another friend was going and i wanted to hide the fact that i want to be wild, nor would i message the event organiser that. If your friends dont accept you as they are or dont want you making new friends...they are not friends!

You have given her a lot of power over what you do.

And if they found out how deeply you're into something....what would happen?

Maybe the woman you are trying to avoid is also trying to make new friends? Maybe she is ditching you!

🤮 sorry op but you come across as having quite a high opinion of yourself as some sort of deep and interesting personality - newsflash - i dont know anyone who doesnt have different sides to their pesonality, its completely normal and not that special! I have friends i go raving with, book club friends who would hate that, hiking friends that i have little in common with besides a love of the outdoors...the difference is i dont try to hide the different aspects from.other people because thats just weird. If a hiking friend shared a passion for drum.n bass then id go to an event with them, if they said they hate dance music - no biggie, we can talk about something else. You sound like hard work tbh

This. I've been increasingly bewildered by your 'personas' and frantic attempts to keep people you deem boring away from you at events you deem interesting. It's a small town! You will meet the EXACT SAME PEOPLE at the school gate and at the bar. The ones you don't see in both places will be close friends with the ones you do.

I live in a very small town and I fucking hate the fact that everybody knows everyone. I don't even have different personas. The one time I went 'out' out here, I woke up to find I'd become the hot gossip for shagging a married man, whom I had not shagged, just talked to. I loved the relative anonymity of London ... though even that's surprisingly small once you know more than about ten people.

Just be yourself in all the places, you daft ha'porth. Wear what you want to wear in each place. Be prepared for gossip.

You'll be fine once you finish high school and start college... it's a great time to reinvent yourself and make new BFFs!
For now.. concentrate on your GCSE's and try to be nice to the other girls at school - even if they are not in the 'party hard gang'!

So why all this kerfuffle including messaging the organiser to tell her you couldn’t now go because Boring Doris was ruining your chance to present your party girl persona to strangers?

And surely if the town is that small, you’re likely to bump into someone else you know at meet-ups? I mean, I live in a city, and I still encounter people I know in unexpected contexts. A friend of mine encountered her driving test assessor at a fetish party!

Actually this,

Everyone is multi faceted OP. You're not a character on a noughties sitcom.

So now you're going after all? But you messaged the organiser to stir up some sort of speculation about lovely but boring Doris? Good that you let the organiser know that even though you know Doris you are really a wild child with a designer wardrobe.

This is all absolutely ridiculous for anyone over the age of 13.

So go.

These friends aren't proper friends if you're worried about them knowing all sides of you. If you're not worried about "sensible" friend knowing different parts of you, it doesn't matter if she's there to see it.

If you are worried about it, then she's not really your friend because you don't trust her.

Either way, do what you want to do and stop worrying about how people perceive you. Just worry about how you feel about yourself.

Just go and talk to other people

or really piss the person off you have by telling her that you don’t like her