My band size has gone down, but my cup size has pretty much stayed the same. Which means that my breasts must shrink somewhat, because of the way bras are measured. When your daughter is much older & not nursing as frequently, they will go down quite a bit as well. I was a 42I when my milk came in with my first, but right now I'm wearing a 38H/I (depends on the bra). In the small sliver of time when my first was slowing down her nursing before I got pregnant with the second (when she was right around 11 mos/1 year) I was in a 38FF, which is more or less a G, and basically means I was down a cup size.
Sorry if that reads as confusing as I think it does.
Just My Size is a suprisingly good source for large-cup bras, but you have to get them online or through their catalogue (there's usually a link to them here on 3FC). Pricier but nicer are British bras from companies like Fantasie and Goddess. You can get truly lovely bras in large cup sizes if you buy from the British companies, but the Fantasie bras in particular cost $60 & up. (Goddess bras are cheaper but not quite as pretty.) Check out
BraExperience for the imported bras. I should note here that I no longer wear actual nursing bras, I just pull up the cup of whatever "normal" bra I am wearing.
One last thing: if you do order a bra online or through a catalogue, you
must measure yourself and check size charts, because once you get past D-cups, cup sizes/names are no longer standard.