A few years ago now, I was diagnosed with cancer. Luckily my prognosis was very good and thankfully, I am healthy now. Following my operation, but prior to me beginning chemotherapy, my MIL offered to come and help us with some 'clearing out'. I really wasn't that bothered but MIL was quite insistent and my husband thought that it might 'help to distract her'. We had almost finished, when out of ear shot, MIL said " Some friends of mine - their son, he was young and his wife got cancer, he re-married within a year after she died. Everyone thought that it was a bit quick but I thought that it was a good thing". I was bemused at first, but then just couldn't believe that my MIL couldn't see that what she was saying might be very upsetting. When MIL had gone home, I told DH what she had said. DH felt that it was odd and described it as a 'stupid' comment.
Recently, MIL has become more difficult, awkward and unpleasant. She had become increasingly over involved and was trying to control many of our decisions. DH is starting to deal with this but finds it hard and would probably prefer to see his DM a little more than we currently do.
I think that I am hoping that you will think that her comment was very unkind, cruel even, perhaps reflecting her true colours and therefore I can maintain my LC stance without guilt or obligation.