The birth of Eamonn 11 days after the general election has been a catalyst for the growing movement in Westminster to make it a more family-friendly environment.
"When I was walking around massively pregnant, people would come up to me and say we must make sure things change - particularly the new MPs and the women," Ms Kelly said.
The Select Committee on Modernisation will consider issues such as electronic voting and changing the hours. Ms Kelly is a strong supporter of these. "Of course we should work a standard working day. And electronic voting would transform people's lives - at the moment it takes about 25 minutes to go through the lobby. You can have amendment after amendment and be going through until the early hours."
Already she has seen a marked change in attitudes. The whips have allocated her a suitable office, with en-suite bathroom. The bath has had a wooden top added to it, for use in nappy-changing, and a small fridge was provided. "It took me most of the 10 days that I was here before the birth to get a room," Ms Kelly said, "but I was one of the first and I certainly got special treatment."
She has been excused from voting until after the summer recess. "The whips were sympathetic and it makes it a lot easier with a 180 majority. But if I voted, it would take up to two or three hours an evening, not a very productive use of time."
The first MP to have a baby was Helene Hayman in October 1976. Now in the Lords as a transport minister, she remembers a horrible time. "It was pretty grim. We were in government, but there was no overall majority and no pairing. There was no alternative to being there: if I didn't go in we would have lost legislation. We were often scraping through on one vote: the Government was being held together by a nappy pin.
"I never took the baby into the Chamber, but of course he was in the House with me. There was a great hoo-ha and criticism about that. I couldn't do right for doing wrong. People thought it was a political gesture - but I was desperate. I wrote to Mrs Thatcher and begged her to pair me with a sick Tory - they were being ferried in by ambulance, on drips - but she wouldn't."
Labour MP Diane Abbot, who had her son, James, in October 1991, also had problems. "The whips didn't allow me to pair. I had to come in for a three-line whip eight days afterwards. I had him in a sling, put a coat over him and walked through the lobby, then people came up and admired him.
"A few days later I was called in by the whips: someone had complained about a baby in the lobby. I thought it was ridiculous: it was OK for David Blunkett's dog to be there, but not an eight-day-old baby. There was no tolerance from the whips, no concessions. From then on I had to leave him with my secretary then dash in and vote.
"I was walking through the House carrying James and the Tory MP Nicholas Soames stopped me and said: 'Haven't you got a nanny for that baby?'"
Ms Kelly has been inundated with support. "My front room looks like a florist's shop, including a bouquet from Tony and Cherie, plus a handwritten note from Tony."
Her constituents knitted jumpers, cardigans, booties, shawls and hats. In Bolton, to which she returns at the weekends with Eamonn and her husband, Derek Gadd, a Labour party constituency agent, people congratulate her in the street. However, there was a small letter-writing campaign in the Bolton Evening News complaining that motherhood would interfere with her duties as an MP.
This does not accord with the facts. She made her maiden speech in the Commons, on low pay and the minimum wage, before Eamonn was born, and has already asked 18 Parliamentary questions, 11 of which were to the Chancellor of the Exchequer about the Bank of England, where she was deputy head of the inflation report division before becoming an MP.
Two full-time secretaries, one in Westminster and one in Bolton, plus a researcher, help her to deal with the casework.
Ms Kelly is determined to use her position to help other mothers.
"There has to be a national childcare strategy to help all parents in this country - not just middle-class women with good careers. And the Palace of Westminster should be leading the way - setting an example for other workplaces."