mean relative

If your sister-in-law's behaviour irks you so much I think perhaps you should reciprocate with the absence of contributions when (if) you go to her. If she brings the subject up, you could say that you thought that's how she preferred things (without adding "since it's the way you behave").

Worth a try?

If you don't want to upset her then there is nothing more to be said. catlover.
If you want to make a point then just take a small token gift when you visit her or as
Lynne59 said ask her directly to bring a contribution. Sounds like this behaviour is entrenched though and not likely to change.

I think you should go on modelling good behaviour ie taking flowers/ wine when you go to hers. Maybe if she stays with you you could pay for drinks out one day and the next day say 'would you like to pay today as we paid yesterday' smiling sweetly. On the other hand you may feel it is not worth a possible fallout!!

What a leech! My husband's sister is similar - she works, as do we - but in the 40 years I've been with my husband, she's had us to her house on 2 occasions. We have taken her out for meals, bought her presents for birthdays, all that. No more. Her own (adult) children are sick of her too.

You can either:
1. Carry on doing what you do, and she won't alter.

2. Have her to your house, but ask her to bring some food or to contribute in some way.

3. Don't have her to your house again.

You have my sympathy. My youngest brother is just the same, never chips in for anything, never says thank you. He is 56 but still regards himself as a dependent child! We just see as little of him as possible, remind ourselves that he isn't going to change now, and grumble to each other to let off steam. Some people just seem to be born selfish.