I dont like her but shes sleeping tonight, in my room too! what do i do?

Im 15 and A twin. Me and my twin were really close to this girl but me and this girl fell out well i got really cross at her because she said thing like i was a ***** and that i need to think abut what i say. Everyone who knows what she said to me was cross at her too because I'm the type of person who gets along with everyone and ive never really fallen out with anyone in the past. Anyway she is sleeping to night because my twin invited her and my mum was like oh just apologize even though i shouldnt be the one to i did and she ignored me, making me embarred and feel like an idiot! So now my mums like well just make friends because i dont want her to feel unwelcome in my house! But i dont want to be friends with her! Not after what she has done and said! Now i feel as though I'm not wanted in my house whilst shes there!