Should I feel slighted or am I just being petty?

A friend of some years called me this morning at 7 a.m. I don’t hear from her regularly. In fact, she has only been to my house once or twice in maybe three years, while I have been to hers several times, most recently for her granddaughter’s 3rd birthday in early December. She wanted me to go, this coming weekend, a holiday weekend, with her to her brother’s mountain cabin four hours away. I used the term ‘cabin’ loosely, as it is more of a mountain mansion. She and her brother don’t get on well, but he is going to check on everything after a particularly cold winter. He told her to come and invite a friend. Her husband and my son are good friends and for the past two years, I have been their designated driver to the World Beerfest which is this Saturday. Getting to the feeling slighted part: her invitation put me fourth in line to go when I asked couldn’t Rebecca or Trisha or Katherine go. Rebecca has a soccer thing with her girls, Trisha is going to a family reunion, and Katherine’s dad is in the hospital. On top of that, she wanted ME to drive her. She is a smoker, and the thought of being confined in a car with her for four hours does not appeal to me. Also, I explained that my little dog is ill and may die before the weekend, to which she basically said OK, she would keep trying to a girlfriend to go with her because she wasn’t going with just her and her brother. I feel like I was too far down the choice line and she would have done well to tell a little white lie when I asked about the other girls and said ‘oh I called you first’ instead of letting me know I was her last resort. Opinions on my decision to forego this trip??