Conversation so far:
Did she win any awards?
Throughout her career as a solo artist, Stefani has won several music awards.
When did she when her first award?
CANNOTANSWER.
What are some of the awards she won?
one Grammy Award.
Did she win any other awards?
four MTV Video Music Awards.

Question: What was her biggest achievement?
Self-contained rewrite: What was Gwen Stefani's biggest achievement?