fortnite

Hi All. My daugther (11) just brought her first Xbox series X. She had looking forward to play Fortnite with keyboard and mouse. But... I can't get it to work. The Keybord works fine in the Xbox menu. It also works in the Fortnite menu and i can also move the mouse. But when the game starts...

Hello, so I am currently in a squad of 3 people, and out of 2 of them, only one of them to hear and communicate with me. They're both on pc. Do you know how to solve this problem, so that I can communicate with both of them?