To be annoyed by this text from my sister regarding Alton Towers?

[Chocolattay]

I have no interest in the place. I have a young baby who’d come with us

It doesn't sound like she wanted help with the children more the fact she wanted you to join in on the fun? Some adults still like rides and with you having a little one would be difficult to go without her. She did say take in turns to watch the pram so if anything it sounds like she invited for your benefit? If you don't want to go just say no