Dd is 3 and it's a long, drawn out event to get her to sleep at night (family bed) if she has napped at all during the day - even 30 min. Plus bedtime is getting later and later and wake time doesn't always compensate, making for a very cranky child all day. . . and so the cycle goes on.
However, I can't seem to stop her from falling asleep during the day. Usually she will ask to breastfeed, get really frantic/insistent and then fall asleep instantly. If I am not home, she usually just passes out in the stroller/sling/hanging out on the couch being read to. The worst is when she has a 'nap' an hour before a reasonable bedtime and then wakes up an hour later raring to go.
My DS was younger when I finally had to cut out the naps, but I started asking him to wait until bedtime to nurse. I made sure I had some cool new craft stuff, stickers, etc to distract him with as well. I also planned activities for the late afternoons...places he couldn't easily fall asleep, like the grocery store (shopping carts aren't very comfy to sleep in). I won't lie, it was cranky h*ll for a week or so, but he sleeps SO much better & longer at night...it's totally worth it, IMO. Hope the transition goes as smoothly as possible for you.
Yeah, you're going to have to manufacture some interesting afternoons for a couple weeks, and I would also at her age ix-nay the nursing in the late afternoons if it's putting her to sleep and replace it with some other comforting activity - she will likely not be impressed with that at all, but you just weather it as you do any other tantrum with empathy but firm resolve. Whatever you do, do not do anything that requires a car trip of more than a few minutes because then she'll fall asleep in the car. Arts and crafts, dance party, something fun. Good luck!