I've namechanged for this.
My sister and I usually have a close relationship. We live about 10 miles from each other. I am the elder by 2 years. Her eldest DC is almost 8 years older than my eldest and we both have two children.
She went back to work term time only once her youngest started school by which time I was at home with my first. Since then I have looked after her children when they have been ill or when she has had to work (she's a TA and has to attend some inset days). Her H hasn't 'been able' (or didn't want to) to take time off to look after his children and I helped out when I could which was a lot including fetching and carrying them to things if it worked out with my DSs.
I did it because it helped and although I didn't expect much help in return I did hope that when I asked for help in the holidays and they weren't actually away that the help would be reciprocated.
To cut a long story shorter, my DS has an eye condition which has necessitated laser surgery under general anaesthetic. As the last bout was in the holidays (this week) I mistakenly thought that they would be able to help (they aren't going on their formal holiday until the October half term) by having DS2 while DH and I took DS1 to the hospital. However I was told in no uncertain terms that her H had booked off the day for the family to go cycling and that it wasn't possible to change it.
Now, if they had been away or had organised for friends to come over or whatever, then I could have understood, but I have had her H's children (as it were) many times so that he could take holiday when he wanted it and then I get it thrown back at me that all the care I did was worthless (well that's how I feel).
Instead I had to ask my Mother (nearly 70) to do a round trip of 200 miles because of their selfishness. Of course if it had been in term time, my Mother would have been pleased to help, but I wanted to take advantage of more local help this time and to save my Mother some driving if it wasn't necessary.
I don't know what to do. Whether to leave it and just say 'sod it' and not help any more (not in my nature) or to confront her either by email or 'phone.
I have been very hurt by it all and it just keeps going round in my head. However I need to sort it for my Mother's sake as we've got a big party for her next weekend.