Jacqueline joined the
World Wrestling Federation in mid-1998 as
Jacqueline. She debuted as the on-screen girlfriend of the
heel Marc Mero and began a feud with
Sable, the estranged wife of Mero. After Jacqueline and Sable traded insults on several occasions, Jacqueline challenged Sable to a
Bikini contest. The contest took place on
July 26 at
Fully Loaded, with Sable winning after she removed her
halter top to reveal a painted on
bikini top. However, the following evening on
RAW, WWF Chairman
Vince McMahon disqualified Sable as
"body paint does not constitute a bikini", and Jacqueline was declared the winner and given the trophy.
Sable recruited
Luna Vachon and the other
Oddities to fight Jacqueline for her, and they helped Luna pin Jacqueline on the
August 10 episode of
RAW. After the match, Sable gave the unconscious Jacqueline's trophy to Luna. Jacqueline demanded that the trophy be returned and faced Sable in an
arm wrestling contest on the
August 17 episode of
RAW. During the contest, Jacqueline broke her grip and pushed the table into Sable's
solar plexus, winding her and enabling Jacqueline to retrieve her trophy. Jacqueline then smashed the trophy over Sable's back. Jacqueline and Mero then teamed together to face Sable and a mystery opponent on
August 30 at
SummerSlam 1998. Sable's partner was revealed to be
Edge, but he was sidelined for much of the match as Jacqueline dominated Sable, preventing her from tagging out. After Sable finally managed to tag Edge, he delivered the Downward Spiral to Mero and then placed Sable atop him, thus winning the match for himself and Sable and humiliating Mero by causing him to lose to his wife.
After Sable defeated Jacqueline in an
evening gown match on the
September 14 episode of
RAW, Jacqueline demanded a singles bout with Sable. The match aired on the
September 21 episode of
RAW. With the revived
WWF Women's Championship on the line (the Women's Championship had been abandoned in January 1996), Jacqueline defeated Sable after Mero tripped Sable and held her foot down, preventing her from kicking out of Jacqueline's
pin. Jacqueline and Sable continued to feud, and Jacqueline cut off Sable's
ponytail on the
October 5 episode of
RAW. While Jacqueline enjoyed a strong run as champion, squashing challengers such as
Starla Saxton a.k.a. (Molly Holly), Mero began to lose more and more frequently. On
October 26, Sable challenged Jacqueline to a title match at
Survivor Series. With
Shane McMahon acting as referee, Sable defeated Jacqueline to become the new WWF Women's Champion.
Jacqueline and Mero separated on the
November 22 episode of
Sunday Night HEAT, and the jilted Jacqueline formed a new
stable of women known as the
Pretty Mean Sisters (a pun on "
PMS") with
Terri Runnels, who was separated from her husband,
Goldust. During a match between Mero and Goldust on the
November 23 episode of
RAW, Jacqueline and Terri entered the ring and
low-blowed both men.