Is it normal that my sister is bitchy with me bcuz of her boyfriend?

since my sister got her first boyfriend she's been so bitchy with me, we used to be bestfriends we would always stick together, but now whenever we are together she always talks about her boyfriend(he's an ass btw) she even called me two-faced and liar just because i caught her talking to him at 4A.M and i asked her what are you doing, srsly? its 4AM and she was like you dont love me you dont want me to be happy...etc.
she was always independent person she always said i dont need a man in my life, now if he didn't text her for a day she would cry her eyes out.
Plus she's ignoring me when he's online, and when she's done texting or talking to him she comes to tell me WHAT THEY WERE TALKING ABOUT, and it suckss!! like okay its a new experience in your life but can you NOT RELATE EVERYTHING TO HIM?! i want to have a sisters talk like we used to do, or forget that, i just want to have a conversation that doesn't INCLUDE HIM, she always listened to me , now she says you're boring stop! let me say something more interesting and she starts talking about him...
so am i being too protective? or this is normal?
help me please, thank you xo.