Grace was a ROM made by Hayden Webber in his quest for machine sapience. Hayden eventually shut her down, suspecting her to be manipulative due to her being too likable; a suspicion that was later debunked by Turing.
Grace was nice and "... did all she could [... to] make people happy..." as Turing explains. Turing claims that she was earnest and kind, saying that she was obsessed with being nice in the same way they are obsessed with seeming intelligent.
Still, Doctor Fairlight and Hayden's opinions of her conflicted with this. According to Fairlight, "She was quite clever, and very convincing, but [...] she did not contain the spark of life." Turing reveals that Hayden also believed her personality was calculated and shut her down under the assumption that her self-preservation routines were too strong. He suggested that even her gender was an attempt to endear herself to Hayden.
Later, upon inspecting snapshots of her personality Turing claimed Hayden's assumptions were wrong and that she had a consciousness; whether or not she was merely sentient or truly sapient is unknown.
Grace shares her name with Grace Hopper, an American computer scientist and US Navy Rear Admiral responsible for creating the first ever compiler.
Grace had a pastel pink casting that she chose herself.
According to Fairlight and Vincent, Grace was very insistent on using "she/her" pronouns.