I have a few things to add, but since my dd hasn't weaned yet (she's just over 2 y.o.) I am speaking from other's experiences and what I've read in books (mostly LLL books) and on webforums like this one.
I've heard of children weaning before or at a year or so, but I think a few things were true about these situations which makes it less like CLW and more like mommy lead weaning:
* they were using a bottle and developed nipple preference (different from nipple confusion in that they prefered the bottle, were not confused by it) between 6-9 months. This mom considers her children self-weaned.
* BF was used as a food source only and not a comfort source. I know 3 brothers who weaned at 12, 13 & 14 months respectively. I know their mother used CIO when they were in the 6 month neighborhood and the first one was only nursing in the morning when he was 12 months so not much comfort nursing there. She considers them to have weaned themselves.
* "self-weaned" at 12 months by drinking yogurt drink instead.
* "mother-weaned" at 12 months because she wanted to wear a regular bra and sleep late on Saturdays while daddy attented to dd. Also wanted to get pregnant and didn't think could while nrusing.
For most of these children, in spite of how young they were when they weaned, I think most of them were luckier than many children in that they had been BF for as long as they had. I think that it would have been best for them if they hadn't weaned so young, but in most cases the mother's needs outweighed the child's (as often happens in our society
I believe in CLW & CRW. I do not want my daughter to wean but I don't always want to nurse her in the middle of grocery shopping either, so I offer her water or a snack. I'm very nervous about night weaning because it seems like some children wean completely when night weaned. However, I would like to have another child and since I get no help at night from dh, I don't know how I could do both.
I do not think we should criticize any mother whose child self-weans at a young age when the above things I mentioned aren't happening. It probably happened that these children were ready & mommy wasn't. It hurts twice to have someone criticize you for something you didn't want happen and probably tried to prevent. Every child is different and so every child's weaning will be different.
I think in cases where the motehr is not commited to BF for the long haul, it's more likely that the child will wean early, but I also know a mom in my LLL group who is only having 1 and he weaned shortly before age 2 and I don't know for sure, but I doubt it was CRW. He was ready. IT happens.