I recently went on holiday for the first time after diagnosis, and I've heard that travelling with a pump can sometimes actually be more of a pain because of the amount of supplies you need to take with you. A few tips I would give (though I'm sure your DSN will tell you anyway):
Buy a frio wallet to keep insulin cool while you're out and about, and preferably check there's a fridge in your room to keep unused stuff cool, or at least air con.
Make sure you take the carbs and cals book away with you, I found it really helpful for trying to carb count my meals.
Have plenty of glucose tablets or sweets with you as you won't be allowed to take drinks on the plane
Make sure you have adequate travel insurance, take her EHIC card with you and make sure you have all the details of the insurance policy and emergency numbers.
Be aware that hot weather can affect blood sugar a lot, I had a few mild hypos due to just walking around in the sun
Take plenty of supplies with you, I had to throw away a pen of Lantus halfway through because somehow some blood got into the vial (didn't even know that was possible!)
Make sure you have a note from the doctor or DSN and a repeat prescription. You'll need to put all the needles/insulin into clear plastic bags at security. Luckily for me no one seemed to bat an eyelid, and no one ever asked for my doctors note but its better to have it.
Keep all the medication in your hand luggage, my boyfriend and I split it between us just in case. Don't ever put it in your hold luggage as the insulin may freeze, or it may (worst case scenario) get lost.
Think that just about covers everything!! If you have any other questions let me know