I would suggest to limit what you tell your family and maybe choose one family member you trust to confide in. The reason I say this is because you WILL begin to feel differently about your H as time goes on and it may be hard to describe that to your family. Eirinn is right, your family will be happy if you M works out.
I have been in this sitch like I said twice. The first time I told my mom and sisters everything. And although they were always supportive, I think they saw my H in a different light. This time around, I've only confided in one sister. I won't have to back pedal this time if things work out.
Again, not saying your family won't be supportive, just saying to be careful how much you share.
Enjoy your vacation. Enjoy your time away. It's sometimes just nice to escape and be busy with loving family.