England won the World T20 in 2009, but have lost to Australia in the final in 2012, 2014 and 2018.
They were without Katherine Brunt and Sarah Taylor, two of their most experienced players, in the Caribbean.
Opener Tammy Beaumont, who was instrumental in England’s World Cup success last year, managed only 54 runs from five innings.
However, young spinner Kirstie Gordon and batter Sophia Dunkley impressed during the tournament.
“They’ve competed with the best in the world without Brunt and Taylor, so that’s a really good sign,” said 38-year-old Edwards, England’s most-capped player who captained them to World Cup and World T20 success in 2009.
“England have unearthed some really special talent in this tournament but some of the senior players haven’t performed.”
Knight said she was proud of her side for reaching another world final.
“We had a lot of inexperience out there. Hopefully this will make it better for them in the future,” she said.