I read your post and was very touched by the emotion of it all. I did some thinking and it seemed very much to me that obstacles were constantly being put in your way to try and stop you going on the cruise.
I don't know how you feel about fate and the unknown but maye somebody up there was trying not to get you there so that you would be home when your SIL passed on.
Who knows, just seems so wierd that you had to overcome so much to get to your cruise to then have that happen but as everyone says, come what may it would have happened.
I myself do believe in fat and what will be, will be. Last December when I was on the Victory doing the Eastern Caribbean (I live in the U.K.) one evening when I was in the bathroom, I saw my Grandmother staring back at me in the mirror and mentioned it to my husband. He laughed it off and said you have one too many! That was late on Thursday, 2nd December (I remember it well).
When I called home on the following Monday (from Florida where we were spending another week post cruise) my Mother sounded fine but I could tell my Son seemed a little distant - I didn't push it as I was so far away but something was nagging at me.
Eventually the next day, I called home again and my Son confided to me that my Grandmother had passed away in the early hours of Friday 3rd December. With the time difference that would have made it late p.m. (circa 23.30) on Thursday 2nd when I saw her staring back at me.
My Grandmother was 102 and she and I were very, very close. I was her first grandchild and her only granddaughter. She had 15 grandsons!.
I felt terible inside as I felt she had been calling out to me. My Mother had made the decision not to upset me and ruin my holiday as she felt I was too far away to do anything.
Anyway, we managed to get back for her funeral - flew the redeye from Miami to Heathrow and then flew straignt up North (she lived in Chester) to attend the funeral.
It taught me that these things will happen and you cannot spend your life not doing things or travelling because you are scared of what might happen.
Fate is fate, I beleive my grandmother called out to me and I believe your SIL was maye trying to get a message through to you and your husband that her time was nearing.
It is a compliment as it shows that you both meant alot to her and she was trying to communicate.
I am glad that things are settling down for you and I am sure in time your husband will understand your reasons. My mother felt it was best to not tell me and I was angry at first but in the end realised that there was not really anything I could do being across the Atlantic but I know that in our own way, my Grandmother and I said our goodbyes via that bathroom mirror on the Victory.
Take care of each other