Drove back to DH's home town (about 100 miles away) this weekend for a family party. The relatives we were visiting live a few miles out of that town, with no public transport, so we hired a car. DH asked SIL, who doesn't drive, if she'd like to come in the car with us, as she lives nearby. Now, if I was SIL and was getting a door-to-door lift (we picked her up and dropped her off), which saved me a train fare of almost £50 (just to get anywhere near to relatives' house), I would definitely offer some money towards the petrol. Am I being unreasonable to expect that she would have done so?
I wouldn't offer my own sister petrol money. It wouldn't even cross my mind. Especially as she lives nearby so you are not going out of your way.
I suppose that because you are hiring a car it does make it a bit different but I still don't think if my sister said 'we have hired a car to go to the party so you might as well come with us' I would give her money. Your dh should have said to her 'shall we hire a car to go to the party?'.
I agree with Savoy and wanna. You were going anyway, it didn't cost you anymore to take her. If you'd wanted to share costs, then you should have said in the first place... "Rather than all 3 of us paying out for train fares and then still not being able to get out to the actual party, so taxis or whatever on top, how about we hire a car and spllit the costs?"
Yes, I see what you're saying about family and that we were going anyway. Guess everyone's family is a bit different, and I suppose I am just thinking if my sister was driving and had paid for the car and petrol, I would feel a bit bad not offering anything. I didn't really expect to get my calculator out and divide the costs up, I just thought as more of a token gesture.