How to get rid of a boring friend? 10 points?

Right so there's this friend who is supposed to be my 'best friend'. But lately I've noticed she's so boring and got such a blank personality, were 14, I've never seen her flirt ever, and if she did and I was there I'd feel so orkward cuz she's so boring and dull! But she obsessed over this guy who doesn't even know she exists, and she aims for boys out of her league all the time, and she doesn't even know their personalities. �In my science cl all the girls are really popular, and bitchy so I don't want to get involved in that but she's the only I've got really in that cl, but I know I sound really horrible but she makes me look so boring and she's not very talkative to others. I'm shy too but I make an attempt to be friendly and nice. It's like I can't get rid of her. Were in year 10 now and I've been friends like of the start of year 8. Were in the same forms and she hangs around in my group. It's not just me though my other mate feels the same, and if I ever fall out with her, her mum always rings mine she's so sad. Seriously it's the holidays but this year I wanna make more friends and she's holding me back. I don't wanna be worse enemies though, i still wanna b mates not just best mates. and if we leave her she's got nobody else to hang out with she's like the odd one out of our group. I know I sound really mean and it is really but I don't wanna spend all my highschool years being held back by her. Please help! Thankyouu Rosie :) x