I've been dealing with managing expectations and iffy personalities lately for our next two trips. Usually we are alone and all is fine but the very first trip was with another couple and it was mostly a disaster. I vowed to make sure anyone else who ever stepped on board with us had very realistic expectations for the good of the group and that entails many things.

I had a brother in law bring his two daughters to a family reunion but he had to work to save his vacation time. He went to McDonalds every morning, for wifi access even though we had it there and stayed there most of the day. I really wish that hadn't happened. On a boat everything gets intensified and I think it is important to make sure one bad apple doesn't spoil the batch. If she has serious work commitments she may not belong on a small boat in the Caribbean. It sounds harsh but I'd have an honest discussion about your expectations and theirs. I've had 9 great trips in the BVI's and one very bad one. If you make sure to let them know about all the not perfect stuff (heat, breakdowns, rocking, rain at night, living in close quarters, connectivity...) and you and they still agree it's a go then you've done as much as you can to make it a successful trip. It may be easier to fix a friendship due to work than to fix a friendship due to someone who had to work while supposedly on vacation. Hope that helps.