The conversations were likely mirror images.

"She felt she wasn't ready," a source close to Ms Berejiklian says of her decision not to  stand for the leadership when former Premier Barry O'Farrell resigned in 2014. "But she is now".

Ms Berejiklian has declared herself a candidate for the Liberal leadership next Monday. If successful, she would become the first female Liberal premier of any state.

Potential opponents are yet to rule out contesting her for the ballot but a Berejiklian victory is being reported as all but guaranteed.

"Mike caught everyone by surprise; there's no set piece," one senior Liberal said. "But she's earned respect for her patience and I think you'll find the party will coalesce around her".

Ms Berejiklian, 46, made her name in the Transport portfolio and was a favourite of former Premier Barry O'Farrell's but declined his urging to stand in a ballot to succeed him, even though her supporters say it could have been a close-run thing.

"She's never really sought profile," says one of her oldest friends, Qantas executive Andrew Parker. "Others [and I] have always encouraged her to speak up much more across a wider range of issues but that's just not who she is".

Friends describe an intensely private woman who is perhaps even closer to her family than Mike Baird is to his; limits herself to one-and-a-half glasses of wine at dinner; likes opera and books about modern history; plays golf; is single and "married to her job".

But those who are out of favour tend to know about it, a Liberal colleague says:  "She's observed well that dictum about not being able to say anything nice... you know you're in trouble if she's not talking to you".

Mr Parker says Ms Berejiklian was on track to become a top executive at the Commonwealth Bank but chose parliament instead. She was elected, in 2003, by the slimmest of margins, less than 0.5 per cent, against independent and former local mayor Pat Reilly.

He says she was drawn to elected politics by a genuine interest in policy and a quiet passion for a progressive brand of Liberal politics, something he attributes to her Armenian background.

(The Treasurer was born in Manly to Armenian immigrants and spoke only Armenian until the age of five.)

"I remember people telling her 'you can't use your last name; your corflutes [political advertising signs] should just say Gladys'," he said. "That background awakened her sense of justice from a young age".

Critics paint Ms Berejiklian as something else: a factional heavyweight who has been consumed with internal factional battles since she was President of the Young Liberals 20 years ago.

She has been a stalwart of the party's now-dominant left wing, or moderate faction, and counts fellow north Sydney Liberals such as Joe Hockey, Trent Zimmerman and Matt Kean as her closest colleagues.

"You're likely to see a very progressive leader," one ally says. "She will be a strong supporter of climate change as scientific fact, progressive policy on immigration and border control and gender equality.

"She will surprise some people".

In the meantime she will have to unite her party. Her expected deputy Dominic Perrottet, from the party's right faction, will go some way toward that.

So far Ms Berejiklian has distinguished herself with a command of policy and detail. But now heavy politics awaits.

Critics query whether she is too nice and too understated to carry the party to an election victory in 2019 and hit back against Labor attacks.

But her supporters say she is ready and capable.

"There's strength and grit there that people don't appreciate," one said.