My little girl (almost 2.5 y/o) does the same thing. It has gotten to the point of being down right painful. She also goes to sleep faster if she can grab the nipple that she is not nursing on. I simply tell her "no, that hurts mommy, you can nurse and cuddle, but you can not grab mommy's nipple". Sometimes she fusses, but she's ok for the most part. When she keeps going for it, I warn her, then simply stop nursing her. Then I bring her back on my lap, tell her that it "hurts mommy" and nurse her again. That went on for a little while, but now I can just tell her "no" or simply move her little hand away and she stops. I love nursing my daughter and I'm not so much afraid of the weaning issue, but I do not enjoy being in pain.

i'll put a different spin on it for you: a blankie is a substitute for *you*, not the other way around.

lots of post-breastfeeding kids like to shove their arms down mama's shirt. my boy does it, even tho he's still nursing several times a day & all night at 20 months. it is painful, especially since i've got thrush again & i don't like him grabbing at my nipples so hard.

i think it's a security & availability issue. your breasts were/are a readily available source of comfort for so long. now that she's busy discovering the world, she doesn't need them as much, but she still likes to know that they're her domain. how to get her to stop? well, i don't have any tried-and-true suggestions, but maybe making your chest less available is your answer. sports bras, modest shirts & sitting in an area that is not easy for her to access your lap might be a beginning (at the table instead of the couch, maybe). i know that i have resorted to standing in lieu of sitting for the sake of keeping him out of my shirt. not very convenient, but immediately effective.