Prince William makes this signature drink for Kate Middleton to mark day end

Prince William and Kate Middleton mark the end of their day with a classic gin and tonic.

As per source close to the couple, William plays bartender for wife Kate after they put children to sleep. The Cambridges share children Prince George, 8, Princess Charlotte, 6, and Prince Louis, 3.

"William will bring Kate a gin-and-tonic," a family friend tells PEOPLE. "They look after each other, but in different ways."

Apart from proving backbone for eachother's royal duties, Kate was spotted "clearly really proud" of her husband during Earthshot Prize Awards ceremony in October. Prince William too, supported Kate as she hosted a Christmas carol concert at Westminster Abbey — they support each other at home.

"The couple is hands-on, friends say, from being there for school pickup to letting the children argue over what songs to play during breakfast," adds PEOPLE.