Rachel's partner Susan Mikula is an artist and photographer. Typically, Susan uses older technologies to produce her photographs, and her work has been featured in galleries across the U.S.

Susan and Rachel met in 1999 when Rachel was working on her doctoral dissertation. She hired Rachel to work on her yard, and the two went on a date.

In early 2021, Rachel went on The Ellen DeGeneres Show to discuss her relationship and how "scary" it was almost losing her partner to COVID-19. She said, "I'm lucky I have the world's greatest relationship, and I'm totally in love, and she's the most important thing in my life." She added, "To feel like her life was on the line, I will never be the same person. It was so scary."