She understands that it’s okay to be insecure sometimes — but that you need to work through it.
There’s nothing wrong with feeling self-conscious of other people sometimes, but you also can’t wallow around in those feelings and have a pity party for yourself. At best, it stops you from working hard and feeling happy, and at worst you might get mind controlled by an evil Asgardian god who looks like a squirrel. Yeah, that happened.
That’s why Doreen is such a go-getter — when she doesn’t feel good enough, she works hard until she does. As she tells that angy Asgardian mind-controlled mob, “Let's be the change we're insecure and jealous about in the world!”
Squirrel Girl knows the value of compromise.
Squirrel Girl is, without a doubt, the most powerful Marvel superhero of all time. No, really; she's beaten up both Thanos and Galactus, who are both big fans of destroying and eating entire planets, respectively. And in “Squirrel Girl Beats Up The Marvel Universe,” a standalone graphic novel written by the regular “Squirrel Girl” team, an evil clone of Doreen literally does just what the title says and takes out everybody in the Marvel Universe, both hero and villain alike.
But what makes this clone so evil? Tony Stark spells it out in the book: it’s her inability to compromise. The real Squirrel Girl always seeks for a solution that will make everyone happy, which is especially vital for a superhero that could get her way at all times if she so chose. If Doreen wanted to she could totally just mow everyone down with her awesome strength and demand that the world kowtow to her will, but she doesn’t, because she believes in fairness and sympathy and understanding other peoples’ mindsets — even when they are jerks who suck.
Also? This doesn't make her a better person or anything, but she's a dang snappy dresser and that's really refreshing.
As we've discussed previously, not a lot of comic book artists really get how important fashion can be in comics, particularly to a female character. Not because girls are obsessed with shopping or anything like that, but because it's a very easy visual signifier for what kind of personality that character might have. And Doreen Green's wardrobe is super, super cute. She experiments with all kinds of different silhouettes and wears a lot of trendy, classy pieces, which is not something you tend to see on someone of a fairly average body type (and with a short, sassy haircut of top of it) in media very often. Show off those legs, girl!