This time was the most stressful for me, cause I hated going from two naps to one, I loved my time in the morning! But it does sound like she's ready to go to one nap.
I wouldn't go cold-turkey though. It'll be hard, but you can try to push that morning nap slowly more towards lunch-time. Make sure she's well-fed in case she konks out right before lunch, but don't worry about it, she'll eat when she gets up.
You kind of have to just play it by ear at this point. Push her in the morning till you can't take it anymore and just have to put her down, then let her sleep. This may cause her PM nap to be later (dinner-time), but push that one too. See if you can get her to go past dinner-time and then put her down for the night, or let her go down for 1/2 hour to an hour, wake her up for dinner, and put her back down.
It sounds cruel, but really, it works. It's hard for a while, but if you can successfully move her nap to after lunch, she'll be on a good one nap schedule. And if she's truly ready for it, it'll be easier than it sounds.
Good luck!
Train up a child in the way he should go; even when he is old he will not depart from it.
(Proverbs 22:6 ESV)