Stadium: Court 6 Round: 26 Ground: Clay
| ITF Women Hammamet | 2018/06/12 09:00 | Natalia Siedliska v Napolitano, Veronica | 6-4,6-1 |
| Antalya, Singles Qualifying W-WITF-TUR-08A | 2018/05/23 07:30 | Julia Stamatova v Natalia Siedliska | 2-6,6-3,6-2 |
| ITF Women Wiesbaden Qual | 2018/04/24 10:30 | Pereira, Teliana v Natalia Siedliska | 2-6,7-5,6-1 |
| ITF Women Wiesbaden Qual | 2018/04/23 12:00 | Sibille, Constance v Natalia Siedliska | 2-6,1-6 |
| ITF Women Hammamet | 2018/04/05 09:00 | Natalia Siedliska v Mirjam Bjorklund | 5-7,2-6 |
| ITF Women Hammamet | 2018/04/03 09:00 | Natalia Siedliska v Markovic, Vera | 6-0,6-0 |
| ITF Women Hammamet | 2018/03/29 11:15 | Natalia Siedliska v Seone Mendez | 3-6,4-6 |
| ITF Women Hammamet | 2018/03/28 14:35 | Natalia Siedliska v Temin, Marie | 4-6,6-1,6-4 |
| ITF Women Hammamet | 2018/06/12 12:30 | Castellano, Sara v Maelys Bougrat | 6-7,6-1,6-4 |
| ITF Women Hammamet | 2018/06/11 11:30 | Castellano, Sara v Tilbuerger, Jantje | 7-6,5-7,6-1 |
| ITF Women Hammamet | 2018/06/10 10:00 | Said, Dalila v Castellano, Sara | 3-6,0-6 |
| ITF Women Manta | 2017/11/27 15:00 | Maria Paulina Perez Garcia v Castellano, Sara | 2-6,7-6,6-2 |
| ITF Women Manta | 2017/11/25 16:00 | Castellano, Sara v Parra Gomez, Juliana Jose | 6-2,6-0 |