Currently the boss of HS1, Shaw was brought in over the summer to look at the performance of the public sector body after a series of failures, including major overrunning of engineering works and a u-turn on promises of multi-billion-pound upgrades as finances have veered wildly out of control.
She also said the way it is regulated "must be" something that's looked at. Shaw will report on her recommendations to the government before next year's spring Budget.
Network Rail's debts stand just short of £40bn. A sale of its properties such as Vinopolis and Brixton Arches is on the cards and could raise £1bn.
Shaw was brought in to assess the funding and structure of the public body while former Transport for London boss Sir Peter Hendy was named chairman to bring the organisation under control.