Thanks, BabySmurf, that's very helpful. I just don't think I have it in me to tandem nurse. I am really ready for a break. It stresses me out to feel like she is so much more dependent on me than on DH--even though I love nursing in many ways, I also feel like it makes it harder for me to get away. When she was younger she would only nurse to sleep and I hated the pressure that put on me when it came to night time parenting--my husband could have done more, perhaps, but she just really wouldn't go to sleep any other way--she even cried when we rocked her. If I think about nursing an infant AND a toddler, my whole mind just screams NO!
I've been taking a "don't offer, don't refuse" approach and she sometimes will go a few days without nursing before bed (she still nurses every morning). For the most part she's dropped the naptime nursing. So we'll see.
My main concern is, if I can't wean her enough in advance of the new baby, will that make it harder on her and make older child jealousy issues more acute--to see the new baby doing what was such a big part of her life until recently? So I feel some time pressure.