My dd2 is almost the same age, and we've been down to 3 breastfeedings for a couple weeks now, pretty much the same schedule as you. I did (over the past 3-4 days) move the 1pm feed back to 11am, and a late lunch of solids, because otherwise she was nursing to sleep for her second nap. R has never taken formula (if she tries a sip, she looks at me like "what are you trying to do?" :roll: ), and won't take ebm from a cup, whether from me or anyone else. I do give her a sippy of watery juice at meals, and she takes what she wants from that.
Don't worry too much about what the nurse says, as long as this is working for you. If she wants more, she'll tell you! :wink: