How do you tell someone no please help!!

Ok, so me and this girl have a rocky friendship she’s very toxic and the reason we first stop being friends is because she was alking about me but that’s not the case. She went to my birthday and it wasn’t fun I didn’t have a good time I wasn’t enjoying myself with her there. Also I have been distancing myself from her she’s noticing so she keeps asking me to come over but I always just come up with an excuse BUT I posted on snap about one of my family members birthday, giving them birthday wishes. She saw... gave no happy birthday....gave no hello but instead texted me with “ok so when’s the party” as if she was already invited...I don’t want her to go because I want to have fun how to I tell her no. Mind you more so I don’t want her to come is because she has a drinking problem so no. Please help! (Mind you my birthday was 2 weeks ago my family members is this weekend so back to back