(Everett, WA)  --  15-year-old Coco Gauff will be joining Serena Williams as part of the U.S. team playing Latvia in a Fed Cup qualifier February 7th at Everett's Angel of the Winds Arena.  The United States Tennis Association announced Williams would be on the team in Everett, and Gauff, Sofia Kenin, Alison Riske and Bethanie Mattek-Sands will join her on the five-member team.  Gauff reached the fourth-round of Wimbledon last year and the fourth round of the Australian Open this year before losing to Kenin.  Kenin is on to the semis after her win over Ons Jabeur.