So far though, she hasn't publicly confirmed she's Muller's running mate. But she hasn't denied it either.
It's a big day today for the National Party. Personally, I don't think this is a done deal.
National MPs have a lot to consider ahead of the vote at midday.
First of all, has Simon Bridges really done that poorly during a time when his opponent has had almost unlimited access to the media? You can't take anything away from Jacinda Ardern for the way she's handled herself.
Once or twice I felt those daily media conferences were turning into party political broadcasts - especially leading up to the Budget - but, overall, she's maintained a steady hand on the tiller.
Where did that leave Bridges? Between a rock and a hard place really, with very little wriggle room and running the risk of being accused of taking cheap shots if he criticised the Government.
He was on the money early in the piece calling for tighter border controls. If we'd gone that way, the lockdown needn't have been anywhere near as severe as it was.
Since then, chairing the Epidemic Response Committee, he's acquitted himself quite well.
Sadly for him, Bridges is weakest where the Prime Minister is strongest - on presentation.
Equally sadly, he's not done anything to help himself by taking lessons. Either that, or he's had a lousy teacher, or just hasn't learned.
So should his caucus flip him now, and pin their hopes on a man who's untainted by any previous activity?
Well, you could argue it worked for Labour last time around.
If they do install a new man now and he goes on to fail in September, then what?
And what of Nikki Kaye in all of this? For my money, she'd actually be a better choice. She's on the left of the National Party, with a track record in office and on the hustings. She's even beaten the PM in the Auckland Central electorate more than once.