She told The Australian that the NBN Co, the company that is rolling out the NBN, would not be able to meet the average revenue per user forecast for 2012-22.
According to the company's annual plan for 2019-2022, released on 31 August, the projected ARPU is $51 by the end of that period, a dollar short of what it has said it needs in order to break even.
In the previous corporate plan, which spanned the years 2018-2021, the NBN Co had said its ARPU would reach $52 by 2021.
Rowland said: "We need to focus on the main game, which is the economics of the NBN, and a lot of that is tied to technology choice and decisions made by the Coalition Government.
"We think there are opportunities for us pick our battles strategically."
She said the Coalition Government's move to a so-called multi-technology mix to speed up the rollout had not delivered as promised.
Advertised rollout targets were compromised to some extent by the travails of the HFC network — activations were suspended in November last year and only resumed in June — and also issues dogging the fixed wireless network.
During its annual results announcement, NBN Co said it was predicting a total outlay of $51 billion on what has been the biggest project undertaken by the government.
The figure has risen steadily from the $29 billion that the Coalition Government said it would spend on the network when it took office in 2013.