Nikki Wood

Nikki Wood is a fictional character created by Joss Whedon in the TV series Buffy the Vampire Slayer, portrayed originally by April Weeden-Washington and later K.D. Aubert.

Not much is known about Nikki Wood, except that she was the second Slayer killed by Spike and that she was the mother of Robin Wood.

Trivia
April Weeden-Washington originally portrayed Nikki. However, when the character was brought back, stuntwoman April was deemed "too mature" by the show's casting directors. They wanted a younger actress, who could seem more like a vulnerable teenage mother, for the role, so K.D. Aubert portrayed Nikki Wood in the seventh season. This means Nikki joins Buffy Summers, Faith Lehane, and the First Evil as characters in the Buffyverse that have been portrayed by more than one actor (not counting stunt doubles).