you are not TA, but neither are he or she imo. From her POV (and in fact EVERYONE's POV it's quite a sensible question. Those sorts of things do happen all the time and one is stuck with a holiday that one has paid for and can't use. If you thnk about it, that's over half your relationship's length away. If i were to b=in the same situation, proportionally, it's like me booking a holiday with my husband in 15 years time - who knows what'll happen before then!