Hey,
So I'm 19 and let me tell you something. I had a 10 girl friendgroup, now I have 3 close friends, and one of those 3 even passed away so It's technically just 2 now lol. I'm guessing you're in secondary, let me tell you right now those friendships, they hardly last forever. 2/3 of the close friends i mentioned are from secondary and that includes the one that passed away so even if it lasts through school, god can intervene and make it not last. so honestly dont put too much stress on yourself thinking "i cant fall out with this girl bc it will end my life" because life goes on and it only ends when god says so.
these kinds of friendships are so draining and i cut contact with many people over the years for similar things because why am i wasting my time that i could have spent on myself, consoling you because "you didnt study" then you ace the test. you clearly studied so dont pmo with your nonsense, yk what i mean.
basically what you have to do is start talking about how busy your life is getting, and make it a big deal. then slowly youre gonna stop replying to this girl as often. when shes texting you the day before an exam abt how shes gna fail, swipe the notification away and silence your phone and revise. dont pay attention to these people because they do it for attention. like academic pick mes lol. eventuallyu she will distance naturally without you being a villain because she will see that you are "busy".
trust me, stressing about keeping this friend is only gonna backfire on you and you will be the only one losing something from this because your peace of mind is so valueable and you need to keep it as much as you can because when you get to uni and become an adult etc, people will be 10x worse and you need to keep ur sanity for then.
idk if i even answered your question properly but trust me, it will be fine in the end. youre at an age where if you lose these friends it is only gods plan working out in your favour, and removing the toxicity in your life. i am at so much peace now with my 2 friends who dont know each other lol and focusing on me myself and i.
also, i have a girl like ur friend in my class who is trying to be my friend and i just give her the cold shoulder. idc if she thinks im rude because other people know im nice, she just likes to show off and im not paying international student fees for uni so that i can come and be impressed by some show off, im here to learn. and you are also in school to learn so focus on learning and getting those 100%s and ignore the showoff, and if your friendship ends then it ends.
love u <3