Am I hormonal or???

My SIL has been pissing me off. She's excited that I'm pregnant but she says things that tick me off. Like "I feel like they are half mine!" And "they are my babies too". Uh, no. I'm carrying them and going through all the pain. I hardly see her unless I'm over at their house and she's bought us two car seats which I'm greatful for. But am I in the wrong for feeling this way? Every time I see her she's all over my stomach which annoys me but I just kind of brush it off. And she keeps saying "my little peanuts!" Like they are hers. I hate that expression everyone uses it. And they don't look like peanuts anymore. They look like tiny humans. I want to say something to her but I'm afraid I'll come off as a bitch. I'm the one going through complications carrying these twins not her :(