Weird to say considering we're on the reddit focused on comics, but this might not be the best place to ask. In the sense that there really aren't a lot of comics aimed at 5 year olds, and the ones that do focus on younger audiences (and which apparantly outsell "our" comic books) aren't really that known here (or at the very least, to me). Because they sell through other outlets than say via comic stores and Diamond.
For example, apparantly Guts has sold more than most all comics published in the last few years. There was an article about it here a while back, I had never heard of this book or the creator. However apparantly this comic and others made by Raina Telgemeier are very popular with young kids. As in way more popular than anything published by Marvel or DC or Archie.
This comic is published through Scholastic, and I'm sure you'll find a lot of other great options on their website which are proven way more popular with the younger kids than what I/we can come up with.
Because I would also say Marvel Adventures titles, or the DCU animated titles which are aimed at kids, or maybe Bone although I would wait maybe a year or two for that one.
edit: sort of cost effective advise, get a cheap 10 inch tablet. Then you can go to the kids section of Comixology and buy titles when they go on sale. If your child actually gets into comics, this will save you a lot of money in the long run vs the short term investment of getting a tablet.
I read his bio about the turn of the century and found that part interesting. Last year, Amazon recommended, "They Called Us Enemy," A graphic novel about the Takei family's interment.
I met George back when I took my step-daughter to a Trek convention in Phoenix for her sweet 16. When he heard her name, Cindy, he started singing THIS to her. She was doubly embarassed because that's the song I sang to her since she was a preschooler.
For anyone interested, there's currently a graphic novel entitled Redbone: The True Story of A Native American Rock Band written by Christian Staebler.
So this post is old and you may be in a different place now, but the graphic memoir Tomboy by Liz Prince might resonate with you. It focuses on the author's struggle growing up and not really knowing where she fit in gender-wise, as she didn't connect with girls but didn't always quite connect with the guys either, and even the phrase 'tomboy' was sometimes too feminine and didn't quite suit her.
Basically, gender is really super confusing and it's okay if you can't quite find your 'label.' Good luck on the continuing journey of self discovery and acceptance and wishing you all the best :)
Oddly enough, last night I read a graphic novel about Lewis & Clark by Nick Bertozzi.
It took less than an hour to read and it was highly entertaining and informative. I recommend it for anyone who forgot everything they learned in the week-long middle-school course -- or for those who are currently studying Lewis and Clark in school.
Talk about a time saver.