My mum and I have a weekend together most years, either walking or a city break (which also usually involves quite a lot of walking). We started doing this (at my suggestion) after I had children so we could have some quality time together when I didn't have to think about child care. My sister has recently asked to join us. AIBU to not want her to come?
She has a health condition which affects her mobility (walking for more than 30 minutes would be difficult) and she also needs easy access to a loo as she needs to go often/urgently. This obviously majorly impacts on what we can do. In addition, I really enjoy my time alone with my mum. We are very close and have a relaxed/enjoyable time together. My sister is often quite stressed and can also be quite prickly (e.g. gets frustrated if I offer help or ask what adjustments are needed, but also gets frustrated if the situation is unmanageable for her) so I find it hard to relax or know what to do.
For background, my parents joined a holiday with my family (DH, DS1 and DS2) a few years ago. My sister asked to join but I said no because it felt too much to ask of my DH. Also (although I didn't say this) she'd had a major falling out with my dad a few months before and I couldn't face this happening again on my holiday. She was very upset and hurt by me saying she couldn't join us - she felt I had treated her very badly and had said no because of her health condition, which she felt was unacceptable. She had a go at me on several occasions over the next few years about it. It would have been difficult to juggle everyone's needs and my whole time would have been spent thinking about everyone else - I'd have come home drained! My parents never asked to come on holiday with me again after the stress it caused which I feel very sad about.
Is it ok to say no to the recent request or AIBU and should I give up my time individual time with my mum? If I say no, what reasons is it acceptable to give? Is it my responsibility to some up with a different suggestion of something to do?