In 1971, at 12 years and 10 months of age, Montgomery suddenly quit tennis, where she was a promising talent, and tried golf, supported by her mother.

[1] At junior level, Montgomery represented Sweden at the European Lady Junior's Team Championship five years in a row, the last three of them with her mother Barbro as non-playing captain and in 1978, at Is Molas Golf Club, Sardinia, Italy, the two of them could share the joy as winners, the first time ever for Sweden in this championship.

[3] Montgomery played collegiate golf at Arizona State University 1977–1981, graduating with a Bachelor of Science in Physical Education and Psychology, in 1980 having made All-Conference Second Team.

[1] In Montgomery's 1981 try to defend her North and South title, she lost in the quarter finale to winner Patti Rizzo on the first extra hole.

As an amateur, she finished tied 6th in the 1981 Women's British Open at Northumberland Golf Club, Newcastle, England In August 1981, she turned professional, at the same time as her friend Pia Nilsson, both with the goal to play on the LPGA Tour.

Montgomery was selected for the Continent of Europe team to compete against Britain and Ireland at the 1981 Vagliano Trophy, but she could not take part, as she had turned professional.

[6] In United States, she played 15 tournaments on the WPGT mini tour, mainly in California 1981–1982, finishing top 4 in eight of them and winning the Coors Classic in Texas, earning US$12,000 on the mini-tour season.

She came close to win the 1982 Women's British Open at Royal Birkdale, England, in August, leading after three rounds, but fell back to a tied 5th place with Debbie Massey and Cathy Panton, three strokes from winner Marta Figueras-Dotti.

Her achievements on the LPGA Tour earned her the 1983 Swedish Golfer of the Year award, male and female, amateur and professional.

Swedish major tournament winner Helen Alfredsson has given credit to Montgomery as one of the individuals most influencing her career.