Hi
A few people on here told you to quit cold turkey. Just so you know, don't risk it! I quit cold turkey and my HORMONES WENT NUTS!!! I got post partum depression so bad, I was hating myself, my husband, my kids. I was like insanely depressed for a week. Also, I think that binding your breasts with a sports bra runs the risk of getting mastitis (plugged milk ducts) that is really painful and makes you run a high fever, so don't risk that either.
If you don't want to nurse her at all anymore, just pump, gradually less and less. You could even give her your breastmilk mixed with formula in a bottle.
Congrats on your new baby!
Marci