Sure! The OC grandparents listed are all parents of canon characters who don’t have names or extended appearances in the games or anime (this would include characters such as Johanna, Grace, Meyer, etc) In some cases my depiction of the grandparents might differ a bit from canon, such as Red and Leaf’s mother having red hair instead of brown, but in general, the game protags’ mothers fit in here! 

I will continue to update the directory as I develop more characters but currently, the identities of the grandparents listed in that section are as follows:

• Aiden Aoyama & Scarlett Yuukoku – Red & Leaf’s parents. Aiden was a Gym Trainer at the Viridian Gym, but goes missing and is presumed deceased 5 years before Red goes on his journey, while Scarlett, is the mother seen in the RBGY and FRLG games. (She also happens to be Blaine’s daughter and only child.)
• Charlie & Flora Oak – Daisy, Gary & Green’s parents. Both were researchers and passed away 7 years before Gary’s journey and 9 years before Green’s journey.
• Isabel Suzuki & Angelo Papavero – Lyra’s parents. Isabel is the mother seen in the HGSS games, while Angelo is a total OC who is a childhood friend and right hand to Giovanni. Isabel broke up with him when she found out that he was involved with a criminal organization and Lyra doesn’t know about him until after the events of HGSS.
• Zack Teruya – Ethan’s father and a single dad. A mysterious foreigner who was taken in by the Daycare Couple when they found him and baby Ethan lost and in need of somewhere to stay. He and his son later take the couple’s surname and move to Newbark, though remain close with them, thus Ethan views the Daycare Couple as his grandparents even if they aren’t blood-related.
• Violet Touma – Reggie & Paul’s mother. She was an archeologist like her husband but passed away in a freak accident while on-site when Paul was a baby. She also happened to be the older sister of Lila, Johanna’s old rival, who is Ursula’s mother, making Ursula the cousin of Reggie and Paul (something she and Paul both like to ignore.)
• Diana Montfort – Hilda & Hilbert’s mother. Nothing much to say here, she’s pretty much just the canon BW mom. Of note is that she’s descended from nobility and inherited a manor house/château (most of which is now a museum) that she and her children live in a section of and which she helps maintain, rather than the regular house the BW protag lives in in canon.
• Harper Montfort & Tia Nocita – Nate & Rosa’s parents. Harper is the twin brother of Diana and while he and Tia aren’t married, they are in a steady relationship. Harper travels a lot and isn’t home very often. He’s had a lot of jobs over the years, including as a Sinnoh Frontier Brain where he became good buddies with Palmer. (He also has some bad habits, especially in his youth, like gambling away the family inheritance, but settled down once his children were born.) Tia is the canon BW2 mom and like in canon, used to be a Pokémon Center nurse.
• Robert Aubert – Serena’s father. He’s a very normal businessman of Kalosian birth who worked for Clay’s mining company in an office/managerial position. He’s not super familiar with the life of a pokémon trainer but supports his daughter wholeheartedly when she sets out on her journey. During XY, he was finishing up business in Unova before moving in with his wife and daughter in Kalos and was very confused and surprised to find out his daughter had helped save the region when he finally made it.
• Zéphyrine Sycamore – Alain & Calem’s mother. The older sister of Professor Sycamore, she passed away when Alain was a child and Calem a toddler and her boyfriend couldn’t handle the loss and abandoned his children not long after, leading the boys to be raised by their grandparents and uncle.
• Orion & Clarissa Kagami – Selene & Elio’s father and stepmother. Orion was a single father who married Clarissa, the canon SuMo mom, when his twins were about 5 or so. He passed away not long before the start of SuMo, and the family’s move to Alola was a way for them to get a fresh start after his mysterious death. (This backstory is still in development, but my idea was for Selene & Elio’s family situation to be similar to Gladion & Lillie’s, with a disappeared dad.)
• Nichola & Auberon Ellington – Victor & Gloria’s parents. In what is now a running theme, Auberon went missing 5 or so years before the SwSh plot, though he actually is alive and is found/comes back after the plot so this one has a happy ending!! Nichola is the canon SwSh mum. Oh, and also Auberon is a fairy prince and one of the two heroes of legend, though his kids don’t find this out until the postgame when Victor meets his old friend “Uncle Bunny” Calyrex.