Stadium: Court 1 Round: 26
| ITF Women Macon Qual | 2017/10/24 14:00 | Guillermo, Lorraine M v Ann Li | 6-7,6-4,0-6 |
| ITF Women Evansville | 2017/07/29 15:30 | Guillermo, Lorraine M v Ann Li | 2-6,6-3,3-6 |
| ITF Women Rancho Santa Fe | 2018/02/21 22:50 | Kayla Day v Guillermo, Lorraine M | 3-6,6-7 |
| ITF Women Rancho Santa Fe Qual | 2018/02/20 18:00 | Guillermo, Lorraine M v Larcher de Brito, Michele | 6-2,6-4 |
| ITF Women Rancho Santa Fe Qual | 2018/02/19 17:30 | Caroline Werner v Guillermo, Lorraine M | 3-6,2-6 |
| Surprise, Singles Qualifying W-WITF-USA-05A | 2018/02/11 20:00 | Guillermo, Lorraine M v Marine Partaud | 4-6,5-7 |
| Wesley Chapel, Singles Qualifying W-WITF-USA-03A | 2018/01/21 14:30 | Reka-Luca Jani v Guillermo, Lorraine M | 5-7,6-2,6-2 |
| ITF Women Orlando Qual | 2018/01/14 15:00 | Guillermo, Lorraine M v Dasha Ivanova | 4-6,6-2,4-6 |
| Daytona Beach, Singles Qualifying W-WITF-USA-01A | 2018/01/07 15:00 | Pierson, Rachel May v Guillermo, Lorraine M | 6-4,7-5 |
| ITF Women Norman Qual | 2017/11/14 16:00 | Pierson, Rachel May v Guillermo, Lorraine M | 6-2,6-4 |
| ITF Women Rancho Santa Fe | 2018/02/21 20:30 | Ann Li v Louisa Chirico | 6-1,6-2 |
| ITF Women Rancho Santa Fe Qual | 2018/02/20 18:15 | Ann Li v Goncalves, Paula Cristina | 7-6,0-6,4-6 |
| ITF Women Rancho Santa Fe Qual | 2018/02/19 17:30 | Wozniak, Aleksandra v Ann Li | 4-6,4-6 |
| ITF Women Rancho Santa Fe Qual | 2018/02/18 17:30 | Ena Shibahara v Ann Li | 5-7,1-6 |
| ITF Women Surprise | 2018/02/13 23:00 | Ann Li v Yanina Wickmayer | 4-6,4-6 |
| ITF Women Midland | 2018/01/31 16:25 | Sachia Vickery v Ann Li | 7-6,6-1 |
| ITF Women Midland Qual | 2018/01/30 15:00 | Ann Li v Goncalves, Paula Cristina | 6-4,6-3 |
| ITF Women Midland Qual | 2018/01/29 16:20 | Ferrando, Cristiana v Ann Li | 6-4,1-6,4-6 |