I'm going to give a bit of backstory so I don't drop feed and looking for honest general opinions as I genuinely have no idea.
I come from a family where eveybody is extremely close for instance I speak to my siblings and my parents every day and my DM multiple times as does my DH with his DM. We have a "proper" get together every other month with our cousins aswell at my DP. Unfortunately my mum has lost her mum and 2 sisters in the last few years so this means that my mum looks to me and only me to help her do all the food and get everything ready with her. We're not talking about dinner for 25 people more like 10 adults and 6 children.
So my AIBU is that sometimes I have absolutely no problem going and helping but other times I just don't want to go to my DPs at 9:am cook all day and then stay there all evening for dinner and also it means that I would normally also spend the entire day away from DD and DH because DH would want to be with her as he's been at work all week. I think my issue is that although I don't mind I feel this massive sense of pressure to ALWAYS go and help like if one time I can't I know that my DM will be severely disappointed sad and lonely as she finds life hard in general without her sisters and DM here. Probably relevant to mention aswell that my DM is absolutely wonderful, does everything for me and my little family and has always been a massive support but just sometimes I don't think she realises the pressures that i face of having my own family and also I don't understand why she can't ask my DB to go and help instead sometimes.