Summer holidays we had a family holiday planned (DH, DD1, DS, DD2 and I, along with my parents) to go to a caravan park or Center Parcs or something. They left planning very late but that's not the point... now they want to go abroad, France or Spain my mother is saying.
DD1 is terrified of flying, she hated planes anyway and always insisted something bad was going to happen on holidays... it was just anxiety and she always loved it once we got there, but at the time she needs lots of reassurance and on the two holidays that my parents have been there they've been dickheads very misunderstanding about it on the plane.
Last year DD had a seizure abroad and got diagnosed with epilepsy; essentially, the bad thing happened. Now she's flat out refusing to go abroad and I don't blame her. I don't really think booking an overseas holiday in so little advance makes sense either.
My parents seem to think it's about cost 
It's not. My mother says she'll pay, we don't need her to, and then she got cross and said I was too proud. I reaffirmed this was about DD and that DH or I would have to stay home with her so it wouldn't really be a family holiday.
She said it was our fault for "giving in" to her fear. Now she went whining to my aunt about my selfishness and that DH puts me up to it, apparently
I'm pretty sure I'm not BU about the last part; but should have I just caved and booked an abroad holiday and forced DD to go? It's been a hugely chaotic couple of months - year, really - for DD especially, and she's just getting better. I don't think it would be fair to do that, but my mother as always has put doubt into my head.
Help?