I am separated from h following his infidelity (long-term affair with a mutual friend, mainly taking place in our house while I was at work). We have been apart for about a year but still see each other lots as he does before and after school care for the dc. Initially the split was supposed to be temporary but I have told him since that it is over and think he accepts this.
Before splitting, I saw his family maybe 3 or 4 times a year. Obviously I would chat to sil at these occasions but we were certainly not close and a few minor but irritating things happened over the years that made me feel, when we split, that not having to go to these family occasions was a bit of a silver lining. I have nothing at all against her, but we are not friends in any sense of the word.
Presents between us have always been joint from ex and me, and she would reciprocate with joint presents for us that were obviously more for h - eg cookery stuff when I never cook. That was absolutely fine. However, last Christmas, and now for my birthday she has sent me a £20 voucher. I feel awkward about this and really don't want to start it. Of course it is a nice gesture but it just feels odd. Her birthday is just before Christmas and I sent her nothing - didn't even occur to me, and her Christmas gift came on the 23rd so no time to send anything back. I don't even have a number or address for her to thank her (not on fb etc), though I could get these from h, but really don't know what to put.
One reason I want no contact is that h told me while we were in throes of my discovery of his affair that he had told his family all sorts of personal stuff about us to justify his behaviour and that, together with the fact that I never clicked with any of them, makes me want to have no contact now. His mother keeps getting the dc to ask me when I will visit her with them and I want none of it, but don't know how to deal with this without sounding churlish.
AIBU?