According to Billboard, Fergie is the female artist of the year on the Year End Chart. Fergie had huge singles and one of the best albums.
Fergie also had 3 songs among the most successful hits, check the list:

Hot 100 Songs:

1 IRREPLACEABLE Beyonce
2 UMBRELLA Rihanna Featuring Jay-Z
3 THE SWEET ESCAPE Gwen Stefani Featuring Akon
4 BIG GIRLS DON'T CRY Fergie
5 BUY U A DRANK (SHAWTY SNAPPIN') T-Pain Featuring Yung Joc
6 BEFORE HE CHEATS Carrie Underwood
7 HEY THERE DELILAH Plain White T's
8 I WANNA LOVE YOU Akon Featuring Snoop Dogg
9 SAY IT RIGHT Nelly Furtado
10 GLAMOROUS Fergie Featuring Ludacris
...
19 FERGALICIOUS Fergie

Top Albums 2007
1 DAUGHTRY Daughtry RCA/RMG
2 KONVICTED Akon Konvict/Upfront/SRC/Universal
3 THE DUTCHESS Fergie will.i.am/A&M/Interscope/IGA

Congratulations Fergie!