The Star Wars actress died on Tuesday
at age 60 after going into cardiac arrest while on a flight from London to Los Angeles. She had been in the U.K. filming season three of Amazon's Catastrophe
, where she portrays Sharon Horgan's mother-in-law.
"Carrie was my friend. It took me three series but I got her in the end. She was the most generous, fun, gifted, smart, kind, funny funny funny person I've ever met," Horgan posted to Instagram following news of Fisher's death. "She certainly wasn't ready to go. I'm so glad we became pals. I'm so devastated at her loss. I want to write about her more but I can't process yet."