Melinda French Gates has entered a new phase of life, and it is “beautiful”, she says. It is five years since her painful, public divorce from the Microsoft founder Bill Gates, and two years since she stepped down from their charity, the Gates Foundation, to focus her full attention on Pivotal, the philanthropic organisation she founded in 2015 to promote women’s empowerment. Her three children have all left home, she goes by “Nonna” to her two granddaughters, and as an empty nester she finds herself in the strange position of having time on her hands.

She has started visiting her local independent bookshop more often, chatting to the staff about what she should read next; when she finishes work at five, she often texts a friend to meet for a walk, and they go exploring new neighbourhoods of Seattle, decaf coffees in hand. She no longer runs daily but insists on a morning stroll to enjoy the natural beauty of her adoptive home town, Lake Washington glittering in late-spring light. This morning, she saw a blue heron, she says, sounding almost boastful.

These seem remarkably modest hobbies for a woman with an estimated net worth of $30bn. When I point this out, she explains how a few years ago she read a quote about how “sometimes we go out in the world for discovery and to learn new things, but sometimes you just need to keep walking the path near you. Walk it over and over again, and you’ll start to see things.” After many years of frenetic international travel with the Gates Foundation, she is choosing the latter.