Roberts was named in the Media Guardian's 2010 power 100. Along with Mumsnet co-founder Carrie Longton, she was voted number 7 in BBC Woman's Hour's "Power List 2013" of the most powerful women in the UK.
In May 2011, Roberts founded Gransnet, a sister site to Mumsnet, for the over-50s.
She has appeared on The Media Show expressing concerns about legislation to regulate blogging, and in May 2013 she appeared on BBC Radio 4's Great Lives programme, nominating football manager Bill Shankly. On 24 December 2015, Roberts was listed by UK-based company Richtopia in the list of 500 Most Influential CEOs in the World.
Roberts married journalist Ian Katz not long before founding Mumsnet. They had four children and separated in 2019.
Recognition
She was recognized as one of the BBC's 100 women of 2013.
Inspiration and motivation
In 2024, Justine Roberts wrote a 'Letter to her younger entrepreneurial self' in which she spoke about how the community around Mumsnet is what inspired her and the purpose they gave her guided the businesses. She also quoted the community's support as the same reason the business "never had to spend much more than maybe £100 on advertising".