The Countryfile star is presenting the Friday and Saturday editions of the programme, following the departure of Jane Garvey and Dame Jenni Murray.
Emma Barnett presents the BBC Radio 4 show from Monday to Thursday.
Rani told viewers: “Welcome to your new-look Friday Woman’s Hour.”
The programme featured a discussion on female superheroes, Netflix drama Bridgerton and the campaign to make virginity testing illegal.
It also heard from teenage activist Anjali Raman-Middleton, who is one of the founders of Choked Up, on calls to improve clean air laws.