I don't know if you can get this done in Switzerland but in New Zealand you can get one of your favourite pictures made into a jigsaw....that would be a fun, kill time and sentimental kind of pressie.
You could make it like a treasure hunt and hide clues around the place for her to find the next pressie.
Another cool gift idea, but this takes time is to make a book with photos and stories about the two of you. So the first sentence would be The first time I met you I thought.....and then you fill in the story. That would be a guaranteed brownie point winner

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You could maybe make a voucher book for her ie This voucher is good for one massage.
Just some random ideas

and I hope you have a super time away for Christmas.