|Birthday||October 8, 1977|
She was born in Knoxville, Tennessee, to Susan Kay Hester (née Taylor, born 1951). Her stepfather, Michael Hester (1957–2016), worked as a bio-medical engineer and was a video game enthusiast. Marchi graduated from the University of Oklahoma in Norman, Oklahoma, with a bachelor's degree in theater and started her professional acting career in 2000.
She married fellow actor Sean T. Perez on August 8, 1999. They divorced on November 21, 2005. Marchi has two step-daughters.
She has performed the voices for several anime roles and is noted for her roles:
- Rinslet Walker in Black Cat
- Liz Thompson in Soul Eater series
- Junko Enoshima & Mukuro Ikusaba in Danganronpa: The Animation & Danganronpa 3: The End of Hope's Peak High School
- Arashi Arisugaw in Tsubasa: Reservoir Chronicle
- Chizuru Maihara in Ouran High School Host Club
- Aki Hinata in Sgt. Frog
- Chloe in Spice & Wolf
- Rebecca Catalina in Fullmetal Alchemist series
- Cana Alberona in Fairy Tail
- Shoko Kirishima in Baka and Test series
- Kiki Seiran in Snow White with the Red Hair
- Quetzalcoatl in Miss Kobayashi's Dragon Maid
- Rias Gremory in High School DxD
Fruits Basket Voicing
- She is born as year of Snake.
- Fruits Basket is her first anime to voice.