Grace is a busy mother and most of the times she has to work at the Grub Buggy, a food company. Grace has been looking for jobs to do, including Harper Futuristics. Seth took Grace on dates ever since Let's Open The Monster Heart!.
In Let's End This! Part One, Grace finds out Seth's true intentions and Grace is brainwashed by Seth as a result of him planting a monster in her brain. Seth uses Grace so that she would be with him. Ryan manages to get her back to the Med Bay with memory loss of remembering Ryan is the pilot of MECH-X4.
In Versus Miami, Graces takes the chance of moving the boys to Miami since Bay City is dangerous with monster attacks. Grace got the offer of becoming a chef in Miami but declines when she figures out Ryan is the pilot of MECH-X4. Grace changes her decision in Versus The X-Weapon when she sees Ryan hurt and injured. In a fight with Traeger, Ryan saves her even though he disobeyed her instructions. Since Ryan saved her life, she now changes her mind to stay in Bay City.
Ryan is Grace's youngest and adopted son. She loves and cares for him deeply.
Mark is Grace's oldest son. She loves and cares for him deeply. In Let's Be Idiots!, he is seen to be protective of guys she dates, such as Seth Harper, possibly as a result of her and Mr. Walker splitting up.
Seth and Grace dated before. They first met in Let's Open The Monster Heart!, when a fire forced them and the rest of the employees, along with Ryan and his friends, out of Harper Futuristics. After Grace grounded Mark for snooping in her business, Seth took an interest in her and the two agreed to go out on a date. However, he later revealed to her that he's behind the monsters, and because of this, she lost interest in him.
Davis Walker is Grace's former romantic interest, revealed at the end of Let's Get The Big Bad! when Ryan found his adoption papers. It can be implied in Let's Open The Monster Heart! that he left Grace and remarried years ago.
- Her first husband Davis Walker remarried years ago.
- Let's Call It Mech-X4!
- Let's Open The Monster Heart!
- Let's Be Idiots!
- Let's Get Our Robot Back!
- Let's Deal with Our Stuff!
- Let's Destroy Some Ooze!
- Let's End This! Part One
- Let's End This! Part Two