My daughter self-weaned at about 2.5 years old.
My son self-weaned at about 1 year old.
I just believed in self-weaning.
I would talk to my daughter about it. If she asked to nurse, I would sometimes just say "not now I'm busy, in a minute...." and then make myself busy and NOT sit down. Then she would get distracted. I also would lessen the time she was at the boob.... not letting her stay on it FOREVER. After a few minutes, I just said 'okay... I have to do things..." then I would get up and make busy. AND, I taught her manners about it... not in public, that she can't just order me to and lift up my shirt... that its my boobs etc. But I'd tell her that gently. So that she didn't feel upset.
Or I did so only IF she asked... not as a matter of "routine." Sometimes s she didn't even ask... thus, self-weaning. So you have to let them not nurse if they don't ask... not just doing it because of "routine."
Or, my friends with kids that age, would put Band-Aids on their nipples and say "Mommy's milk doesn't work...." or "Mommy has a boo-boo..." and they said that worked for them.
Or, you allow it only at certain times.
I got pregnant once, before my daughter self-weaned. But that ended up a miscarriage. But I got pregnant after that, with my son.
all the best,
Susan