England are missing a clutch of names from their triumphant World Cup campaign on home soil last year -- usual skipper Zoe Stratford and Abbie Ward are pregnant, and Emily Scarratt and Abby Dow have retired.
Megan Jones will captain the Six Nations squad, comprising 22 forwards and 16 backs, which boasts 25 World Cup winners.
Seven players are uncapped at the senior international level -- Christiana Balogun, Millie David, Haineala Lutui, Annabel Meta, Sarah Parry, Demelza Short and Jodie Verghese.
"It's great to be back together, ready to earn the right again following the Rugby World Cup," said Mitchell.
"The impact of the tournament across the country has been outstanding, and it's reflected in the incredible ticket sales."
The New Zealander, a former men's All Blacks coach, said he was excited by the energy the younger players would bring to his squad.
"What is important to me is to stay open-minded about player combinations, and I will observe how people compete against each other and deal with that type of pressure," he said.
"It's just down to who is going to take the handbrake off, attack it, and express themselves in our game."
England open their campaign against Ireland at Twickenham on April 11.