(Note: I do not know and can not provide any advice on the medical benefits of CSP or Med Jet Insurance.)
I reviewed medical coverage as part of trip cancellation insurance a couple of years ago. My primary goal was to get medical coverage, not trip interuption coverage. I found 10-12 outfits that will sell you coverage of some type, and I stuided a couple that I thought might offer what I wanted at that time.
I doubt any insurance company is going to issue coverage which would be effective for your trip since your daughter's condition is a pre-existing condition. The companies I found would only cover a pre-existing condition if you bound coverage (e.g. paid for your policy) within 21-30 days of the date on which you first incurred an expense for the trip (often airfare). Further, coverage was only primary if you bound coverage within 7 days (as I recall) of the first expense incurrence. By the way, the companies I looked at did not transport you to your hospital of choice, as mentioned for MedJet upthread. Rather they transport you to the nearest facility that can provide the care needed. So that could be 10 miles up the road from your hotel in Curacao-you can't just say "Take us home". You also should check your medical insurance policy on what, if any, coverage you have outside the USA, and what you would have to do to have it in force, such as pre-authorization.
You and your daughter will have to decide whether she should go on this trip, using of course input from her medical team. While speaking to them, you might inquire what sort of medical services are available in Curacao, especially since from your description, it seems there in no clear diagnosis yet.
If you decide to cancel the trip, you should study the rules of the airline in which program you booked your award, and see if they have provisions for medical cancelations. Two years ago, I canceled a UA award when medical issues arose. Their rules at that time were that to have the miles redposited back to their original account, you had to send a letter to UA outlining the issues involved, along with supporting documentation from the doctor. At that time, you had to pay $50 (perhaps per ticket) to have UA consider the matter, a sunk cost regardless of how they rule. My advice is that you prepare a letter for the lead doctor to sign which outlines the medical problem in summary, and states that he/she does not believe you daughter should travel to Curacao on March 29, 2015, and that she needs you to look after her as well. YMMV but I can not imagine UA turning you down. Regardless of whether they do or not, you should get the fees and taxes you paid back.
Other airlines have other rules, and some have none. For those, I would send the same letter and documentation but add that you are seeking a one-time exception as the cancelation is important for your daughter's health.
