Slobig attended School Without Walls High School and trained at MarVaTeens Gymnastic Club. She was the Maryland state champion and placed third all around at USFG regionals. As a freshman Rebecca impressed by hitting her routines at big meets with highs on bars and beams coming at the EAGL Championships. She saw action in all 12 meets and was consistent on the bars with hits in nine of 12 meets. She had eight top 10 and five top five bars finishes. Her first collegiate victory was versus Rutgers and she followed that performance by tying Karla Hairston's school bars record to place third at the EAGL Championship. Slobig had four top 10 beam finishes and placed eighth at the Bahamas Sunshine Cup. She competed in her only floor routine of the season at NCAA Southeast Regional.

As a sophomore, Slobig was named to the All -AGL second team on beam. She was also a regular on bars, beam ad floor. She had seven top 10 finishes on bars including two thirds with a best score versus Rhode Island as WVU shattered the team bars record. She had two firsts and two seconds on beam. She was considered WVU's top beam worker with six scores of 9.7 or better. She recorded a season high 9.875 to finish second in the home finale. Slobig also had seven top 10 showings on floor with a season high 9.875 in a fifth place showing at EAGL championships.

As a junior, Slobig overcame consistency problems that plagued her as a sophomore and freshman to emerge as a dependable performer on bars and beam. Her floor routine improved dramatically from first meet to final meet. She ranked 19th in the nation on beam and 20th on bars. She was named to the All-EAGL first team on floor and second on bars and beam. Slobig had three career high 9.9 routines including second place finishes against Towson, Michigan State, and George Washington and Rutgers. She also had eight top 10 bars finishes and had four routines in a row to close out the season. She placed fourth at EAGL championship and won beam at Towson versus Auburn, Maryland and Radford, and against Michigan State. Rebecca had eight top five finishes in 12 routines with seven scores of 9.8 or better while setting a career high of 9.9 twice at the Auburn quad and home finale versus George Washington and Rutgers. Slobig capped the George Washington and Rutgers meet with first place career highs on the floor routine with her third 9.9 of the day. She sat out the Temple meet breaking a string of 27 consecutive meets. Returning for her senior year, Slobig had developed into one of WVU's most consistent bars and beam workers. She showed marked improvement each year and was one of the teams top gymnasts and was a potential All-American on bars and beam. She had also set career highs on three events as a junior.