All-American Girls Professional Baseball League ®
| Team | Position | Uniform # |
|---|---|---|
| 1946 Kenosha Comets | Second Base & Third Base | 7 |
| 1947 Peoria Redwings | Shortstop & Third Base | 8 |
| 1948 Peoria Redwings | Third Base | 8 |
| 1949 Peoria Redwings | Shortstop & Third Base | 8 |
| 1950 Peoria Redwings | Third, Shortstop & Manager | 8 |
| 1951 Peoria Redwings | Second Base | 1 |
| 1952 Kalamazoo Lassies | Second Base & Third Base | 11 |
| 1953 Kalamazoo Lassies | Second Base | 11 |
| 1953 Muskegon Belles | Second Base | Unknown |
| 1953 Rockford Peaches | Second Base | Unknown |
| 1954 South Bend Blue Sox | Second Base | 20 |
Mary was named co-manager for the Redwings for the 1950 season. Pepper showed great hustle on the diamond and was a solid, strong-armed third baseman. While playing for Peoria she went from utility to starting shortstop. She could be heard playing her harmonica or singing for her teammates. She worked in a Christmas card factory while playing in the league and enjoyed riding horses, playing basketball and swimming to stay in shape.
Mary passed away in July 1, 1977.
| Year | Ga | AB | R | H | 2B | 3B | HR | RBI | SB | BB | SO | AVG |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1946 | 103 | 310 | 32 | 47 | 3 | 0 | 0 | 20 | 42 | 17 | 38 | .152 |
| 1947 | 67 | 194 | 17 | 35 | 1 | 0 | 0 | 16 | 12 | 17 | 14 | .180 |
| 1948 | 122 | 428 | 49 | 76 | 6 | 3 | 0 | 29 | 37 | 50 | 53 | .178 |
| 1949 | 97 | 330 | 21 | 54 | 3 | 1 | 1 | 22 | 17 | 25 | 24 | .164 |
| 1950 | 109 | 412 | 54 | 97 | 12 | 2 | 0 | 24 | 37 | 45 | 40 | .235 |
| 1951 | 102 | 374 | 47 | 66 | 8 | 2 | 1 | 22 | 27 | 36 | 30 | .176 |
| 1952 | 65 | 196 | 23 | 41 | 1 | 0 | 0 | 2 | 5 | 18 | 15 | .209 |
| 1953 | 91 | 311 | 22 | 54 | 2 | 1 | 0 | 17 | 13 | 32 | 21 | .174 |
| 1954 | 84 | 252 | 16 | 53 | 5 | 0 | 0 | 17 | 8 | 23 | 20 | .210 |