Is it unreasonable to not always invite my sister to everything that me and my mum do? I'm not talking holidays and big things (which she's always invited to) but a walk or a lunch in a cafe? I'm talking about once every maybe 5 things I.E 4 things together and 1 thing just thr two of us. They do things alone but mainly when I'm at work. Sometimes I just want time with my mum.