score:4
It is usually possible to book hotels with the possibility to cancel although this may incur an extra charge. In my experience this is usually a premium of 10-20%.
For the air fare (assuming you are flying) cancellable fares are usually much more expensive. You could always book a fully refundable fare now to guarantee your flight and then when she passes her exams cancel it and re-book a non-refundable fare which will probably be more expensive by then but you cannot win them all.
(This mostly expands on what @jcaron suggests in comment but I have given more detail)
Upvote:3
I guess this is a bit late in the day, but if you book your flights with lastminute.com then they offer CFAR insurance as an option - they call it FullyFlex. It costs about 10% of the cost of the flight (which if you book a budget flight without any frills, often doesnt amount to that much) and it will refund you 90% of the flight in the event that you choose to cancel without reason. The refund is a voucher to spend on lastminute.com, but given that they sell flights for most airlines (and hotels etc), is fairly usable. I have used this in the past and cancelled, the process if fairly swift, I request the cancellation and voucher, a few hours later I have it and it is valid for a year I think. So if you are <90% certain that you will take the flight, then (IMO) it is worth it.
Upvote:4
"Cancel for any reason" policies are rare and even if you find one, they tend to be very expensive and only refund a portion (usually half) of the trip cost.
Rough estimate: You can expect to pay around 10%-20% of the total trip price as a premium and to cover half of the trip price as "cancel for any reason".
So unless, there is a high chance of you having to cancel, this does not make financial sense.