Because she is the wife of Home Office minister Tony McNulty, opponents in politics and the press viewed her with suspicion, publicly doubting whether she could operate independently of government pressure.
At the time, Ms Gilbert kept her own counsel, saying only how delighted she was at getting the job. But now, at the end of her first month in the role, the new chief inspector of schools has hit back at the accusations, pledging she will not be a party political "stooge".
"Those comments upset me. I was surprised they were quite as prevalent as they were," she said. "I thought my record was strong enough to have countered that.
"I think most people would say I had a pretty strong background for the post. I would say my record of achievement spoke for itself."
Ms Gilbert took up the post after six years as chief executive of the London borough of Tower Hamlets. She was previously in charge of education for the borough and saw the number of local children achieving five good GCSE results increase from barely a quarter to more than half.
A former headteacher who was made a CBE this year for services to local government and education, Ms Gilbert has spent the past eight months heading the Government's long-awaited review on personalised learning.
But it was not just education that drew her to her new job. The deciding factor, she said, was the opportunity to turn Ofsted into a wider inspectorate of education, children's services and skills.
From April, it will merge with the Adult Learning Inspectorate and parts of the Commission for Social Care Inspection and HM Inspectorate of Court Administration to create an empire that she estimates could touch the lives of a quarter to a half of the population.
"The big thing for me is creating this new organisation that's very much focused on users, that hasn't got a heavy hand and is looking at inspection in a more proportionate way," she said.
With a background so heavily invested in teaching, she already has clear ideas about areas in schools that need attention.
The evidence suggests that teaching is improving, she said, but improvements in numeracy and literacy have begun to plateau, which is where personalised learning could help and provide benefits.
"I am very positive about the teaching profession. I think that most teachers want to do a good job," she said.
When first asked to head the Government's review into personalised learning, she admits that, like many, she was confused about what the concept meant.
"I don't think we are going to be too prescriptive," she said, "and I don't really worry about a personalised learning strategy. I think that would be the kiss of death.
"We are trying to be as pragmatic as possible in the report and look for ways to develop ideas and roll out some of the good practice that is going on."
Union concerns that personalised learning mean teachers having to produce learning plans for each pupil were unwarranted, she said. "You can see why they would worry if it did place an additional burden on teachers, but I don't think it need do. It can be built into the structure of the week."
Last month The TES revealed that Manchester university academics had found significant numbers of schools were "borrowing" good teachers to get through inspections. Ms Gilbert doubted this could happen under the new framework. "It would be really hard to borrow teachers with two days'
notice. And even harder for inspectors not to notice," she said.
And what of home life? Does she discuss Government policy with Mr McNulty? "I hardly see him actually. That is mainly my fault, with the hours I work."
THE GILBERT CV
Christine Gilbert became HM Chief Inspector of Schools on October 1. Her promotion to the pound;150,000-a-year post follows a career in education and local government.
Ms Gilbert spent 18 years in teaching, eight as the headteacher at Whitmore high school in Harrow, north-west London. She then became director of education of the borough.
In 1997 she moved to the east London borough of Tower Hamlets as corporate director in charge of education and from 2000 was the council's chief executive.
She was appointed a CBE for services to local government and education in the 2006 new year's honours list.