oh, can i relate. my siblings did this to me a couple years ago. you can skip this if you like but if you want to hear the tale, get this;
three years ago, my dad had a massive stroke and very nearly died; oldest sister and i did split shifts 6 hours on/off to stay with dad around the clock the 26 days in ICU. older sis 2 is completely useless in hospital situations and bailed. younger brother made an appearance at the hospital and did more than older sister 2 but still not much.
i took the night shift with dad when he was most restless and trying to get out of bed (he was restrained) when he really got bad i'd sing him "We Go On" and The Promise from the WDW Millenium cd, and he always settled down and fell asleep with a smile on his face.
10 days into dad's recovery my MIL had a massive internal hemmorhage and almost died too. DH and i went back and forth between hospitals in different states.
whole time once dad was able to speak we all talked about going to WDW soon as he was able. that got him well, talking about past trips, looking forward to future ones, with my dd (his only grandchild)
after the hospital, DH and i brought dad home to our house, nursed him back to health (mom unable to care for him, long story) and little did i know that oldest sister was already planning the trip we'd all talked about and not telling me. dear sister also ceased helping with dad's care when he left the hospital, DH and i did it all.
they went on that trip: three months after he got out of the hospital, and six weeks after he left my care.
they didn't invite me. why? because oldest sister disapproves that i no longer practice the family religion! guess i'm good enough to take care of dad but not to share the celebration after his recovery with! i still cry if i think about it.
Dad felt so bad about how hurt I was (i didn't complain or anything about it to my sibs, it would have done no good anyway. they all knew it would hurt me and said as much afterward but did it anyway! my other 2 sibs felt like skunks they told me later but they couldn't fight big sister
i think my DH may have mentioned to my parents how hurt i was not just for myself but also my daughter because the whole time Dad was recouperating (they are very close) he kept saying he couldn't wait to take her back to WDW.
well, after he gets back from the trip with my sibs, dad calls me up and says he wants to go back with my DH and DD; and we did, that week! i planned the trip in two days and we had a blast. he told me once we got there that 'traveling with the others was quite a different experience" and that ours was "the golden trip".
in the end, he's been back to WDW with us a couple other times since then (soon to go again in a couple weeks) but never with my sibs! we treated him last year to a week concierge at the GF and we all had a great time.
families can be so weird, and no one can hurt you quite like a sister can

((((((hugs)))))) my understanding and my heart goes out to you!
geek
p.s. on our next trip my in laws are coming, our first trip to WDW since MIL almost died on us! i plan on spoiling her!

i better pack lots of kleenex cause i know the happy tears will be abundant.