Michelef, Just book the tickets, or at the very least tell her you have already booked the tickets.
I am English, lived in the US for a while and this is what I observed: In the UK, when times are tough, people will say "if you need anything, make sure you give me a call" and of course, you are never going to call and say 'I've been up all night sick please can you bring over a casserole'.
In the US neighbours just turned up on my doorstep after I had a baby, with casseroles. And one time when I was very sick, a neighbour went to market and bought fresh veg and fruit for me, without asking. I was so grateful.
I have learned that sometimes it is better to just DO rather than ask.
However, I also have an elderly mother, and I know they are proud and stoic and have had a lifetime of being self suufficient, and it is very difficult for them to accept help, or even kind offers of a holiday. It's a tough one!
