Well, one of the things I discovered when I became sober is that I NEED alone-time. It's not a fear of being around peope, but a desire to be 'quiet'. I really need it on a regular basis. I love inter-acting with people, but am relieved to be able to go home at the end of it all. This is your home and your private space and you have it set up in a way that works for you. It gives you comfort. Therefore, no one should enter your home if you don't want them there.
I choose to not tell anyone, outside of SR, about my addiction. I struggled with the idea for awhile, feeling I was being dishonest. But, bearing your soul to people does not necessarily make you an 'honest' person. For me, I'm an honest person in the way I live my life every day. I did a lot of soul-searching. What I discovered is that most people have things about themselves that they rarely, if ever, share. From my point of view, addiction is a part of me, but not all of me. There are many other aspects as to who I am as a person.
Feeling that you have an obligation to a friend who invited herself and her child to come and stay with you is only that - an obligation - one of the 'shoulds' in our lives. My goal is to remove as many of those 'shoulds' from my life as I can. It's all about intention - you do something because you want to do it for some reason, not because you should.