See now, my sister does not assert herself (and I actually think this is a common e1 trait and perhaps a IXXJ trait? -idk)...because she believes people should already know without her telling them. Like she totally thinks her rules are the 'standard rules of conduct and human decency' and any breech is a purposeful violation. But it sounds like maybe you don't? That you at times question the validity of how you feel? The thing is though...is that is how you feel. If you don't want someone coming over into your space with a baby...that's okay. It is okay for you to express that...and it doesn't need to be 'understood' by others. You can also even say..."I am so happy for you and your new life. And I would like to set aside some time that we can spend alone."