Thank you for all the replies - I'll try and answer some of the things. Sorry if I miss anything. I really do appreciate the help and concern (even from the people who think I'm nuts) and promise that I've thought this through.
Yes, it might be rainy/floods (it's mid October so unlikely to have started according to our apartment hosts, but they also lend wellies if needed). I'll keep an eye on the weather and have promised mum a weather forecast for our 'destination' before we pack.
Not crossing over the Brexit deadline so that's ok. Thank you for the info about phones - I'm delighted as I thought I'd have to nick her phone and put roaming on!
Re the surprise element - there are a few things that make me sure this is ok.
- She has actively chosen to keep it a surprise (I agree I wouldn't like this - but she does!)
- She knows she can change her mind at any time and have me tell her where we're going
- Knowing her, if she knew it would not increase the pleasure just make her worry about arrangements. This takes that away from her.
- If she knew, she'd try to persuade me to let her help pay, or to go somewhere cheaper, because she wouldn't feel I should spend so much money on her. She deserves to be totally spoiled with it being too late to worry about that!
- She knows it's a trip just not abroad, so the only tricky thing is going on a plane not a train and things like liquids going into hand luggage.
- She may well suspect anyway because I had to tell her I was taking her on a surprise trip AND fake a ruse to get her passport in the same week when I saw her recently...
Health stuff - we are very close (probably partly because she's been single for a long time) and I know every twinge, never mind health condition, that she's ever had. I feel confident I can relay her medical history and medications accurately for insurance. But also - remember that I can easily tell her I'm taking out travel insurance without telling her it's abroad, so if I get stuck I'll just ask her the questions I need to know.
The medication she takes (and the different one that I take) doesn't have to have a letter with it. I know she doesn't use a pill box so will bring the packaging as she does on our other holidays. She has T2 diabetes which is treated differently to T1 (and is very borderline T2). By the way, she's under 12 stone, for those worrying about her weight, so yes technically overweight but not in any way that should affect travel. I'm not far off her weight myself!
I can't think of what else - oh I'm going to call the EHIC people today (now in fact) so thanks for that too.
It's genuinely helpful to have people questioning me so I can make sure I've asked myself all the right questions and done all the right prep. But I agree that 70 isn't at all old (certainly not for her!) and not yet time to worry about heart attacks in the airport over a wonderful surprise of going on a 2 hour flight to somewhere she's always dreamed of going.