Stadium: Center Court Round: 25
| Sharm El Sheikh, Singles W-WITF-EGY-09A | 2018/11/21 09:15 | Natalia Siedliska v Daria Kuczer | 7-6,3-6,1-6 |
| ITF Women Muzaffarnagar | 2018/11/13 06:40 | Natalia Siedliska v Melanie Klaffner | 6-7,1-6 |
| ITF Women Heraklion | 2018/11/07 09:15 | Natalia Siedliska v Argyrokastriti, Marianne | 4-6,2-6 |
| ITF Women Toronto | 2018/10/31 16:40 | Katherine Sebov v Natalia Siedliska | 6-3,6-2 |
| ITF Women Toronto | 2018/10/29 14:00 | Kinard, Tori v Natalia Siedliska | 1-6,4-6 |
| ITF Women Toronto | 2018/10/28 16:35 | Layne Sleeth v Natalia Siedliska | 2-6,1-6 |
| ITF Women Toronto | 2018/10/27 14:00 | Mikhailuk, Alexandra v Natalia Siedliska | 2-6,4-6 |
| ITF Women Poitiers | 2018/10/20 07:30 | Natalia Siedliska v Diana Marcinkevica | 2-6,1-6 |
| ITF Women Jablonec Nad Nisou | 2018/12/05 14:35 | Proese, Natalie v Wysoczanska, Katarzyna | 1-6,2-6 |
| ITF Women Milovice | 2018/11/30 10:00 | Proese, Natalie v Nefisa Berberovic | 6-4,3-6,2-6 |
| ITF Women Milovice | 2018/11/29 13:30 | Timea Jaruskova v Proese, Natalie | 1-6,3-6 |
| ITF Women Milovice | 2018/11/28 09:00 | Karolina Vlckova v Proese, Natalie | 3-6,6-4,0-6 |
| ITF Women Milovice | 2018/11/28 09:00 | Karolina Vlckova v Proese, Natalie | 3-6,6-4,0-5 |
| ITF Women Milovice | 2018/11/27 13:20 | Proese, Natalie v Linda Sevcikova | 6-3,6-1 |
| ITF Women Milovice | 2018/11/26 14:00 | Proese, Natalie v Wysoczanska, Katarzyna | 6-3,6-4 |
| ITF Women Trieste | 2018/09/05 07:30 | Proese, Natalie v Avvantaggiati, Vittoria | 1-6,6-0,0-6 |