Ms Miller made Queensland political history on Thursday, as the only backbencher since the estimates hearing process began in 1994 to attend every single committee, grilling the state's ministers over how they administered their budgets and portfolios.

Having fallen out with the government late last year, when she resigned from the cabinet after she was demoted by Premier Annastacia Palaszcuk following an Ethics Committee finding of a "pattern of reckless behaviour", Ms Miller has been beholden to no one.

Describing herself as a true Labor "warrior", Ms Miller could not be rebuked by the government during her pointed and often uncomfortable questioning of her former cabinet colleagues, for fear she could quit the party.

Her exit would plunge into chaos the Palaszczuk administration, which holds an equal number of seats with the LNP on the floor of the Parliament and governs through the support of independents.

The Bundamba MP became the opposition's greatest asset, landing blows and scoring points where they did not, backing ministers into corners and striking, while refusing to back down herself.

While the opposition MPs leading the questioning struggled to find traction or a narrative over the seven-day hearing sessions, Ms Miller picked apart government policy, or criticised it straight-out.

In that, she was fearless, questioning the worth of a $180 million program personally favoured by the Premier, given how few jobs it had created, as well as stating scepticism over her government's attempts to lower cost of living.

She returns to Bundamba with the entire government and their most senior bureaucrats having promised personally to examine local issues she has raised, as well as having made her point - that right now, she holds the whole government by a string.

And she is not afraid to tug on it.

Jo-Ann Miller's best estimates moments:

• Wrought a promise from the Director-General of the Transport Department, a $6 billion portfolio, that he will travel to her electorate to look at issues such as a congestion bottleneck, the need for a left-hand lane and the possibility of a train service later than 1am, but earlier than 5am, for her constituents who travel to the Valley for late-night music shows.
• Queried the $180 million spend on the Premier's favoured policy, Advance Queensland, given the 148 direct jobs it has so far created. "That works out, so far, to approximately $405,000 per job," she told Innovation Minister Leeanne Enoch. "That seems awfully expensive. Would you like to comment on that?"
• Threatened Deputy-Premier Jackie Trad with a right-to-information request if she did not receive further information about infrastructure planning and spending, telling her colleagues "because I am clearly not satisfied with the response given by the Deputy Premier".
• Referred former health minister and LNP leader Lawrence Springborg to the police, alleging he had misled a parliamentary committee over information he gave to an estimates hearing in 2013, which was contradicted by the Barrett Centre report handed down earlier this month, over the timing of the decision to close the centre.
• Tackled the Clerk and the Speaker of the Parliament on whether or not they knew whether MPs were paying their electoral cleaning staff the correct award wages - they do not - and the parliament's failure to pay for relief staff when electoral staff take holidays.  
• Requested both Premier Annastacia Palaszczuk and Mines Minister Anthony Lynham establish a Royal Commission into the re-emergence of black lung disease across the state, as well as champion retired miners and their families over barriers they face accessing medical treatments, given the upfront costs they have to pay for scans to see if they suffer from the disease only being reimbursed if they have it. "It's a catch-22 ... they can't afford it."
• Asked the government to consider allowing car registration to be paid monthly, like insurance, for those who struggle to afford up-front payments.
• Calling on the government to do more over the "price gouging" from toll companies, if payments were missed.
• Questioned the 'real world' effectiveness of another hallmark policy - its 'Back to Work' employment package, which requires job seekers to contribute to training components of the plan. "Minister, what I'm getting at here, is that there are other areas of regional Queensland where the ordinary person who is out of work simply cannot afford to co-contribute to this type of training. That's what I am concerned about. I'm not being critical of you, Minister. What I'm saying is that, that could turn people off from even applying for this."
• Questioned Deputy Premier Jackie Trad over the value of her overseas trade missions. "I'm just wondering how much was expended for the minister's component of these trips (and) whether you could provide the dollar value of trade that has been invested to date in Queensland as a result of the trip".
• Forced Child Services Minister Shannon Fentiman to reveal that the department received 361 harm reports in the last year, of which 121 were substantiated.
• Was credited by the Premier, in the middle of estimates, to be doing "probably more work than the Leader of the Opposition.

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