Mary Jane is a pale, chubby girl with black hair and bangs. Her birthday can be an event in the game, the player can give her the Deck of Cards, Bug Spray, or a MedKit/First Aid Kit. The best option is the Deck of Cards. If the player runs low on supplies and doesn't give her Water Bottles or Soup Cans, she will run away into the wasteland to become a highway woman and the game will mark her as dead. She can also play the tuba, and it's possible to send her out in the wasteland overnight to practice.
She can become a mutant if she is bitten by a mutant spider, the player does nothing about bugs, or if the puddle of green goo isn't cleaned with a Boy Scout Handbook, Suitcase or Gas Mask. This means she will not require Water Bottles to survive, but she will require more Soup Cans as a result. She also becomes immune to Sickness, Tiredness, Insanity, and becoming Injured. If Mary Jane mutates before the family is followed from their expeditions, the bandits will still take control of the area, but will never attack the family as long as she is the only character to ever exit the shelter. This mutation is a feature exclusive to Mary Jane.
Mary Jane is a female character with black hair and pale skin. Her hair is styled in a high ponytail, held up with a pink hair tie. She has a white shirt, a navy blue skirt, white socks and brown shoes. It's worth noting that she looks very similar to Ted, whereas Timmy primarily has Dolores's features.
When a mutant, she has purple skin and has rips in her clothes, and her limbs will appear unevenly proportioned in size. She will also have a giant underbite and a hump on her back.
When insane, she will pose like a chicken and stand on her seat, except from when she's Tired. Mary Jane's 3D model (appears when scavenging) shows her playing a tuba outside the shelter and she sometimes makes a tuba sound.
Find diary in the scout guide.
Read it: You end up regretting it, as what you see in there is... disturbing.
Don't read it: She thanks you and burns the diary.
Mutant Mary Jane doesn't require any water to survive so it can be very good if you run low on water.
- When insane, she can destroy or eat the Axe, the Radio, a Can of Soup and the Flashlight, claiming the batteries from the Flashlight/Radio will give her 'energy.'
- She is the only character that can turn into a mutant.
- In a balance update, the chance for Mary Jane to become a mutant was decreased.
- She is the character that has the least resistance to insanity. It is possible that it's because there are too many events that heavily damage her sanity.
- She becomes the most useful character when she is a mutant because she cannot be killed or kidnapped by the raiders or bandits during scavenging, as she always returns safely. She can also drive away bandits that attack you, being very helpful.
- If Mary Jane turns into a Mutant, on a day, there will be an event that gives you the option to talk to Mutant Mary Jane. If you do, she could run away, injure most (if not all) family members, or the family discovers she is the same as always (Mary Jane does nothing in this case).
- Even if Mary Jane was in the shelter with other one member, that member has a chance to get Insanity, because she is not a very social character. This may be why she spends most of her time playing her instrument (which her family members don't think is very professional since they hoped she couldn't find the tuba when the event comes up).
- She is one of 3 characters that can really age in the game, the others being Timmy and Ted. Aging is shown by Timmy and Mary Jane both having birthdays, and Ted growing a beard. This has changed in the Reatomized version, though, because in this version, Dolores' hair grows too.
- Sometimes in the journal, a drawing of her playing a saxophone is seen, even though she plays the tuba. (The most frequent time this drawing can appear is in the Thunderdome events).
- Mary Jane's face, when she is a mutant resembles the popular Troll Face meme, however, this is not a reference, making Mutant Mary Jane look like the Troll face was completely unintentional and simply just a coincidence (or is it?) 
- Her name is also another word for marijuana due to similar abbreviations.
- Mary Jane will often ask for soup after an expedition.
- According to a sanity/birthday event, Mary Jane hates checkers, and this event may destroy the checkers if used.
- Mary Jane may be one of the most useful characters in game, due to her being able to turn into a mutant; she becomes immune to most status effects, scares off raiders, and does not need water; which is more important than food, since it is possible to live longer without food than water.
- When Mary Jane becomes mutant and she is starved for an extended period of time, there is a chance that she will actually eat one of the family members.
- Many people believe that you can get Mutant Mary Jane if you keep cockroaches in your base. This is actually not true at all. All the cockroaches do is make people sick.
- If Mary Jane is not rescued during the initial scavenging part, sad tuba noises can be heard as Ted/Dolores jumps into the shelter when the time runs out.
- Mary Jane grows her hair in The ReAtomized Version. It becomes longer and messy.
- Insane Mary Jane will do the chicken pose.
- Unlike 60 Seconds!, in Reatomized, it is impossible to survive for longer than about 200 days, as Mutant Mary Jane can only defend once, and then defends twice and leaves the shelter.
- There's a rare event which happens if Mary Jane is not rescued while scavenging: Mary Jane comes to the fallout shelter, claiming that she hid inside a broken refrigerator to survive the nuke blast. This is a reference to Indiana Jones and the Crystal Skull where Indiana Jones hid inside a refrigerator to survive the explosion of a nuclear test, it may also be a reference to “Billy the Kid” from Fallout 4.
- In Spider-Man, he has a second girlfriend named Mary Jane. It is also possible that Mary Jane's spider mutation is a Spider-Man reference, since Mary Jane mutates by being bitten by a radioactive spider.
- Several Tweets from the official Robot Gentleman Twitter account use the word 'McDoodle' when referring to the Family and their full name: https://twitter.com/search?q=%23McDoodleFamily,%20OR%20%23McDoodle,%20OR%20%23TedMcDoodle,%20OR%20%23DoloresMcDoodle,%20OR%20%23TimmyMcDoodle,%20OR%20%23MaryJaneMcDoodle%20from:robotgentleman&src=typd