- "I love all my grandchildren the same."
- —Gramma defending the claim that she favors Manny.
Gramma is the maternal grandmother of Greg, Rodrick and Manny Heffley and their twin cousins Malvin and Malcolm, and the mother of Susan Heffley, Aunt Cakey, Aunt Veronica, Aunt Audra and Aunt Gretchen. She tends to favor Manny, but she denies this. According to Greg in the online version, she has many photos of Manny and only has one of Greg's head from the back and none of Rodrick. She was married to Grampa, whom she either divorced or is a widow of.
Gramma first appears during Halloween where Rowley Jefferson uses the bathroom. Greg and Rowley hide in her house after being chased by teenagers, but are forced to head back home by Susan because it's a school night. On the bus drive to school, Greg feels sort of bad that the teenagers had teepeed and egged her house, but rebuffs his guilt by stating Gramma is retired and probably didn't have anything to do.
As a way for Greg and Rodrick to earn Mom Bucks, Susan has the boys rake Gramma's leaves. Due to Rodrick's advice of tying the bag from the bottom, Gramma was not happy to hand over her hot chocolate stating they hadn't raked any of her leaves properly, but had to, as she made a deal that if they rake, she will give them hot chocolate. Manny is dropped off at Gramma's house while his parents go on vacation, because she favors him which she repeatedly denies stating that she "loves all her grandchildren equally".
Greg wishes that he could switch spots with Sweetie during the blizzard, because Gramma overfeeds him. When they went over to her house, she had given the guest room to Sweetie and forces Greg and Rodrick to sleep together on her pull-out couch.
Gramma is seen in a few of the flashbacks Greg has from when he was a baby. It's revealed that when Greg was being born Gramma was watching Rodrick. When they returned from the hospital Greg found out he wasn't an only child. Later on in the book she is seen in a picture.
Easter was spent at her house (last year and this year) and Greg talks about how it is boring but used to be fun when Meemaw used to hide eggs. She was also seen searching for Meemaw's ring. Later, Greg tossed the Magic 8 Ball near her fence.
Gramma likes to play bingo, but is not as serious as some of the ladies. She also reads tabloids, which leads to problems, as Susan claims that tabloids are full of lies. However, Gramma seems to believe the tabloids, such as when she would not answer her phone because she read that it erases the memory of the elderly people. Susan also thinks she has extrasensory perception meaning she is or might have been a psychic or influenced by one.
Gramma is an elderly lady with white curly hair covering her ears. Her facial features are very similar appearances to those of her daughter Susan (including the shape of her nose). She mainly appears wearing normal clothes and a skirt throughout the series.
For more images, see: Gramma/Gallery
- Diary of a Wimpy Kid Online (First appearance)
- Diary of a Wimpy Kid
- Diary of a Wimpy Kid (film) (Mentioned only as "Grandma")
- Diary of a Wimpy Kid: Rodrick Rules
- Diary of a Wimpy Kid: The Last Straw
- Diary of a Wimpy Kid: Dog Days
- Diary of a Wimpy Kid: The Ugly Truth
- Diary of a Wimpy Kid: Cabin Fever
- Diary of a Wimpy Kid: Do-It-Yourself Book
- Diary of a Wimpy Kid: The Third Wheel (Flash-back appearances and mentions)
- Diary of a Wimpy Kid: Hard Luck
- Diary of a Wimpy Kid: The Long Haul (Mentioned)
- Diary of a Wimpy Kid: Double Down (Mentioned)
- Wimpy Wonderland