dandydon once bubbled...
How old is your daughter, and are all three of your certified with at least a little ocean diving experience? It'd help if you're profile gave more info...?
Good questions!
The Flower gardens are a great dive site. There is plenty to see and the Oil Rig dives are remarkable. (1000' of water in some cases, so good boyuancy control is required to stay within Rec Limits). Reefs are within 60' to 120'. The sea conditions can be a bit rough. (as was my experience anyway) These sites are very far from the land and the weather can kick up things in an alarming way. Our trip experienced mad current and high seas. If you get lost here...YOU GET LOST HERE. (always carry a "dive alert" and safety sausage...which are required there anyway)
Not to say that it is a bad place for newer divers (I was one when I went there-did my AOW on that trip), but I must say that this is a place that "You Never Know What You Will Get" .
All that said, My time there was remarkable. We all had some great dives. I was on the MV Fling (aparently the MV Spree is the same deal.) Ours was a nice boat- but as to luxury...all they had to offer was "3 hots and a cot". The "hots" were good simple food and the "cot" was a berth with 3 other men...engine noise and all that...
Hope this helps in you adventure choice,
Peace, DG