| ITF W25 Malibu | 11/04 17:00 | 54 | Guillermo, Lorraine M v Alexa Noel | 7-5,6-3 | |
| ITF W80 Tyler | 11/01 16:00 | 26 | Guillermo, Lorraine M v Jamie Loeb | 3-6,4-6 | |
| ITF W80 Tyler | 10/31 16:55 | 25 | Jaimee Fourlis v Guillermo, Lorraine M | 0-6,5-7 | |
| ITF W80 Tyler | 10/29 15:30 | 54 | Guillermo, Lorraine M v Hourigan, Paige Mary | 6-1,6-2 | |
| ITF W80 Tyler | 10/28 15:00 | 54 | Sophie Chang v Guillermo, Lorraine M | 4-6,5-7 | |
| ITF W25 Dallas | 10/24 15:00 | 26 | Guillermo, Lorraine M v Olivia Tjandramulia | 4-6,6-7 | |
| ITF W25 Dallas | 10/23 17:20 | 25 | Guillermo, Lorraine M v Emily Appleton | 6-3,6-1 | |
| ITF W25 Dallas | 10/22 15:00 | 54 | Guillermo, Lorraine M v Abdelouahid, Hind | 6-1,6-0 | |
| ITF W25 Waco | 10/18 17:55 | 27 | Guillermo, Lorraine M v Contreras Gomez, Fernanda | 2-6,3-6 | |
| ITF W25 Waco | 10/17 17:55 | 26 | Guillermo, Lorraine M v Melany Solange Krywoj | 6-3,6-4 | |
| ITF W25 Waco | 10/16 18:20 | 25 | Burrage, Jodie Anna v Guillermo, Lorraine M | 0-6,4-6 | |
| ITF W15 Norman | 10/04 16:20 | 27 | Guillermo, Lorraine M v Dalayna Hewitt | 6-4,2-6,4-6 | |
| ITF W15 Norman | 10/03 15:00 | 26 | Guillermo, Lorraine M v Chavatipon, Charlotte | 6-3,6-7,6-4 | |
| ITF W15 Norman | 10/01 15:00 | 25 | Guillermo, Lorraine M v Lisa-Marie Rioux | 6-4,7-5 | |
| ITF W60 Templeton | 09/24 17:20 | 54 | Montez, Pamela v Guillermo, Lorraine M | 6-4,6-2 | |
| ITF W60 Templeton | 09/23 21:15 | 54 | Lee, Sarah v Guillermo, Lorraine M | 3-6,3-6 | |
| ITF W25 Redding | 09/10 21:25 | 25 | [500] Guillermo, Lorraine M v Talaba, Gabriela [307] | 3-6,6-4,4-6 | |
| ITF W25 Fort Worth | 08/03 17:15 | 28 | Guillermo, Lorraine M v van Nguyen, Chanelle | 6-4,5-7,3-6 | |
| ITF W25 Fort Worth | 08/02 14:00 | 27 | Guillermo, Lorraine M v Whittle, Sophia | 6-0,7-6 | |
| ITF W25 Fort Worth | 08/01 14:00 | 26 | Guillermo, Lorraine M v Amy Zhu | 6-4,6-3 | |
| ITF W25 Fort Worth | 07/31 16:55 | 25 | [340] Talaba, Gabriela v Guillermo, Lorraine M [464] | 3-6,6-1,4-6 | |
| Ashland, Simples W-ITF-USA-23A | 07/24 16:25 | 25 | [459] Guillermo, Lorraine M v Maegan Manasse [338] | 3-6,1-6 | |
| Ashland, Simples W-ITF-USA-23A | 07/23 14:50 | 54 | [498] Alycia Parks v Guillermo, Lorraine M [459] | 4-6,2-6 | |
| Ashland, Simples W-ITF-USA-23A | 07/22 15:20 | 54 | Boyd, Jasmine v Guillermo, Lorraine M | 1-6,0-6 | |
| ITF W60 Berkeley | 07/15 22:35 | 54 | [456] Guillermo, Lorraine M v Carter, Hayley [445] | 4-6,6-2,4-10 | |
| Honolulu, Simples W-ITF-USA-20A | 07/09 00:40 | 54 | Kinard, Tori v Guillermo, Lorraine M | 2-6,6-0,10-8 | |
| Denver, Singles Qualifying W-ITF-USA-28A | 06/19 16:00 | 25 | [459] Guillermo, Lorraine M v Chieh-Yu Hsu [432] | 4-6,4-6 | |
| Nonthaburi, Singles W-ITF-THA-01A | 05/28 05:30 | 54 | Guillermo, Lorraine M v Jandakate, Chompoothip | 4-6,5-7 | |
| Nonthaburi, Singles W-ITF-THA-01A | 05/27 04:30 | 54 | Guillermo, Lorraine M v Runglerdkriangkrai, Apichaya | 6-0,6-1 | |
| Nonthaburi, Singles W-ITF-THA-01A | 05/21 07:45 | 25 | Peangtarn Plipuech v Guillermo, Lorraine M | 7-6,4-6,6-3 |