Stadium: Court 4 Round: 25 Ground: Clay
| ITF Women Sao Paulo | 2018/03/01 14:00 | Stewart, Katerina v Haas, Barbara | 6-1,2-6,1-6 |
| ITF Women Sao Paulo | 2018/02/27 13:00 | Carolina Alves v Stewart, Katerina | 5-7,1-6 |
| Sao Paulo, Singles Qualifying W-WITF-BRA-02A | 2018/02/26 14:40 | Stewart, Katerina v Piai, Eduarda | 6-0,6-3 |
| Sao Paulo, Singles Qualifying W-WITF-BRA-02A | 2018/02/25 16:00 | Stewart, Katerina v Lucero, Carla | 6-2,6-0 |
| Sao Paulo, Singles Qualifying W-WITF-BRA-02A | 2018/02/24 15:30 | Stewart, Katerina v Julieta Lara Estable | 7-5,6-2 |
| Wesley Chapel, Singles W-WITF-USA-03A | 2018/01/24 16:35 | Stewart, Katerina v Whitney Osuigwe | 3-6,5-7 |
| ITF Women Orlando Qual | 2018/01/15 15:00 | Stewart, Katerina v Chihiro Muramatsu | 3-6,6-7 |
| ITF Women Orlando Qual | 2018/01/14 15:00 | Stewart, Katerina v Leduc, Catherine | 6-2,6-1 |
| ITF Women Rancho Santa Fe Qual | 2018/02/19 19:00 | Robin Anderson v Kremen, Ilona | 6-3,6-0 |
| ITF Women Rancho Santa Fe Qual | 2018/02/18 22:00 | Thoma, Alexis v Kremen, Ilona | 0-6,0-6 |
| Surprise, Singles Qualifying W-WITF-USA-05A | 2018/02/11 17:00 | Weinhold, Ashley v Kremen, Ilona | 6-4,6-3 |
| Wesley Chapel, Singles Qualifying W-WITF-USA-03A | 2018/01/21 16:30 | Marcela Zacarias v Kremen, Ilona | 6-1,6-1 |
| ITF Women Orlando Qual | 2018/01/15 15:00 | Reka-Luca Jani v Kremen, Ilona | 6-0,6-4 |
| ITF Women Orlando Qual | 2018/01/14 21:00 | Kremen, Ilona v Wachaczyk, Julia | 6-2,6-3 |
| Daytona Beach, Singles Qualifying W-WITF-USA-01A | 2018/01/07 16:30 | Kremen, Ilona v Hanna Chang | 6-7,6-7 |
| Obidos, Singles W-WITF-POR-12A | 2017/10/18 15:00 | Kremen, Ilona v Dalila Spiteri | 3-6,3-6 |