Appearing before the education select committee today, Spielman, who took over the role from Sir Michael Wilshaw in January, said she had no plans to break up the inspectorate.
She said splitting the two remits would create more complexity in its work and make information sharing across education and social care more difficult.
Her comments came in response to Conservative MP Lucy Allen, Conservative MP for Telford, who asked Spielman whether a split would help improve inspections of children's social care given concerns raised from within the children's sector to the committee that Ofsted was not helping to improve children's lives.
"No. I don't think it would," Spielman said.
She added: "Looking at the interests of children where different parts of their lives intersect is an increasingly valuable piece of what we do.
"If there was a separate inspectorate it would create another interface that local authorities had to work across. It would create another organisation that we had to constantly be sharing with. I think it would create more complexity rather than solving things."
The education select committee has long called for Ofsted's social care and education functions to be split.
In April 2011 it recommended that the inspectorate's two functions should be separated as Ofsted's remit was too big to operate effectively. However, this was rejected by the government and was also opposed by the Association of Directors of Children's Services.
In July 2016 the committee once again called for Ofsted to be split, to give social care a higher profile amid concerns that Ofsted's senior management lacked children's services expertise.
At the same time the committee also rejected the candidature of Spielman, who co-founded the Ark academy chain, for the top role at the watchdog, citing fears that she did not have a clear understanding of the wide range of services Ofsted inspects.
At this week's hearing Spielman was also asked to address concerns that children with special educational needs and disabilities (SEND) were being asked by head teachers to stay away from schools on days when Ofsted inspectors visited.
Emma Hardy, Labour MP for Kingston upon Hull West and Hessle, said: "We often hear about schools during Ofsted inspections asking certain children who are SEND to miss school on days when inspectors are in.
"I've had parents contact me with exact examples of when this has happened.
"The aim here is all about improving the school's Ofsted rating, which isn't a true reflection of the school."
Spielman said: "I wish people would tell us. I've heard that people have heard from constituents or others that this has happened in a particular school but very few specific reports that we can follow up on flow through to us.
"I would urge people if they know of a school where this has happened to send that in to us."
James Frith, Labour MP for Bury North also raised concerns that schools are failing to identify SEND pupils in need of additional support through an education, health and care plan, due to a disincentive in the funding system. Currently schools have to spend £6,000 from their budgets on support for SEND pupils before they can apply to councils for additional support.
Spielman said it is "definitely an area of concern" that schools are acting in this way.