| ITF W15 Cancun | 01/22 15:00 | 28 | Natalia Siedliska v Maria Jose Portillo Ramirez | 6-7,2-6 | |
| ITF W15 Cancun | 01/21 15:00 | 27 | Julie Belgraver v Natalia Siedliska | 3-6,3-6 | |
| ITF W15 Cancun | 01/20 19:15 | 26 | Mayuka Aikawa v Natalia Siedliska | 4-6,2-6 | |
| ITF W15 Cancun | 01/19 18:15 | 25 | Maja Radenkovic v Natalia Siedliska | 1-6,6-7 | |
| ITF W25 Vero Beach | 01/11 18:35 | 25 | Natalia Siedliska v Sophie Chang | 1-6,1-6 | |
| ITF W15 Antalya | 11/13 08:50 | 28 | Natalia Siedliska v Diana Shnaider | 2-6,1-6 | |
| ITF W15 Antalya | 11/12 08:35 | 27 | Doga Turkmen v Natalia Siedliska | 1-6,3-6 | |
| ITF W15 Antalya | 11/11 06:25 | 26 | Zoziya Kardava v Natalia Siedliska | 6-7,0-6 | |
| ITF W15 Antalya | 11/09 10:45 | 25 | Melisa Ercan v Natalia Siedliska | Retired | |
| ITF W15 Antalya | 11/04 10:00 | 26 | Lavinia Tanasie v Natalia Siedliska | 7-6,2-6,6-3 | |
| ITF W15 Antalya | 11/03 08:20 | 25 | Zoziya Kardava v Natalia Siedliska | 6-3,2-6,1-6 | |
| ITF W15 Antalya | 10/15 07:00 | 27 | Sonay Kartal v Natalia Siedliska | 6-0,6-4 | |
| ITF W15 Antalya | 10/14 07:00 | 26 | Eszter Meri v Natalia Siedliska | 3-6,0-6 | |
| ITF W15 Antalya | 10/12 07:00 | 25 | Irene Lavino v Natalia Siedliska | 6-7,4-6 | |
| ITF W15 Wanfercee-Baulet | 08/24 11:20 | 25 | Natalia Siedliska v Silvia Ambrosio | Retired | |
| ITF W15 Erwitte | 08/19 10:00 | 26 | Sofia Nami Samavati v Natalia Siedliska | 7-5,6-4 | |
| ITF W15 Erwitte | 08/18 09:00 | 25 | Joelle Lilly Sophie Steur v Natalia Siedliska | 3-6,4-6 | |
| ITF W25 Koksijde | 08/08 13:00 | 54 | Berta Bonardi v Natalia Siedliska | 7-6,6-7,10-6 | |
| ITF W15 Knokke | 07/31 12:05 | 28 | Natalia Siedliska v Selena Janicijevic | 6-4,5-7,2-6 | |
| ITF W15 Knokke | 07/30 10:10 | 27 | Michaela Bayerlova v Natalia Siedliska | 6-3,2-6,1-6 | |
| ITF W15 Knokke | 07/29 14:00 | 26 | Bojana Marinkovic v Natalia Siedliska | 2-6,4-6 | |
| ITF W15 Knokke | 07/27 12:05 | 25 | Noa Liauw A Fong v Natalia Siedliska | 4-6,3-6 | |
| ITF W15 L'Aquila | 06/24 10:00 | 26 | Emily Seibold v Natalia Siedliska | Retired | |
| ITF W15 L'Aquila | 06/23 08:30 | 25 | Caijsa W Hennemann v Natalia Siedliska | 2-6,4-6 | |
| ITF W15 Antalya | 06/10 07:00 | 26 | Natalia Siedliska v Ilay Yoruk | Walkover | |
| ITF W15 Antalya | 06/08 08:40 | 25 | Natalia Siedliska v Anet A Koskel | 6-2,6-0 | |
| ITF W15 Antalya | 06/04 07:25 | 27 | [309] Manon Arcangioli v Natalia Siedliska [489] | 7-6,2-6,6-2 | |
| ITF W15 Antalya | 06/03 07:30 | 26 | Vivien Sandberg v Natalia Siedliska | 2-6,3-6 | |
| ITF W15 Antalya | 06/01 07:00 | 25 | Iman Khan v Natalia Siedliska | 6-4,0-6,1-6 | |
| ITF W15 Antalya | 05/19 11:50 | 25 | Natalia Siedliska v Mayuka Aikawa | Retired |