In her first season race walking (spring 1996), Jill qualified for the NAIA nationals and finished 2nd. By her second season, she won the NAIA's. Her breakthough time of 13:16.16 was not only a huge PR at 3,000m, but also established the NAIA and senior national records at that distance as well. Like many records, that mark has since been broken. Jill continued with racewalking on into the summer following graduation and placed 5th at the USATF Track & Field Nationals. This effort qualified her to compete in the World University Games.

Taking her degree in Chemistry from Cedarville, Jill pursued her masters degree in Atmospheric Science at Purdue University starting in the fall of 1997. Peters continued to coach Jill. While most of the coaching was accomplished via email, the two usually saw each other once every two weeks for either a race or practice. This combination worked well. Cobb won the Penn Relays two years in a row (23:09 and then 22:35) and also won the USATF 15K Championships in a time of 1:11:38. She also competed on her first Pan Am Cup team.

As the spring of 1999 rolled round, life got quite hectic. Cobb started off 1999 with the first of three straight 2nd place finishes at the USATF indoor nationals in Atlanta - gradually lowering her PR's at that distance to 12:48. Then, as graduation neared, Cobb competed in USA nationals, qualifying for, and then competing in the 1999 World University Games. She then rushed back to defend her Master's thesis, move to Fairborn (Ohio), and started work with Ball Corporation, all within a three week period. "There are so many unique and different areas of analysis to delve into", said Cobb about her work at Ball. "Investigating new atmospheric correction techniques has been my most satisfying experience."

Once settled at her job, Jill started gearing up for the 2000 Olympic Trials. Along the way she walked a 1:34:50, well under the then Olympic A standard of 1:36. She raced powerfully at the trials but eventually finished 7th.

2001 was her big year. After placing third at the USATF 20k nationals in Eugene, Oregon, Jill competed in the IAAF world Championships, the Goodwill Games in Australia, and the Pan Am Cup in Ecuador.

Her last race walk was the 2002 World Cup in Turin, Italy. Cobb got married in 2002 and had her first child, Daniel in July 2003.

20K World Championships
2001 – 25th – 1:42:43 – Edmonton, Canada

20K World Cup
2002 – 69th – 1:47:35 – Torino, Italy 
1999 - 64th - 1:40:30 - Mezidon, France

20K Pan Am Cup
2001 – 9th – 1:48:24 – Cuenca, Ecuador 
2000 - 16th - 1:43:57 - Poza Rica, Mexico 
1998 – 9th - 1:47:15 – Miami, FL

World University Games
2001 - DNF