Why does Shego love her little Princess? Well… you know.
There are so many reasons.
One: Kim Possible is a very attractive young woman. Cheerleading and saving the world have blessed her with what Shego considers a damn-near perfect body. Plus, being a goody two-shoes does seem to give her this kind of innocent, angelic glow… something Shego can admire even if she doesn't understand it.
Two: Shego is a bit of a narcissist. She adores herself, from her looks to her body to her vast intelligence to every other innumerable trait she possesses. The thing she loves most about herself however is not her ass, or her uncanny knack for sarcasm… it's her spirit. Shego prides herself on her determination, her loyalty to her beliefs, and the life she sees flaring in her eyes every time she looks in a mirror. Kim Possible possesses that same spirit; the same fire lights up her eyes.
Three: Shego is a step above other villains; there is only one person she considers a rival in terms of strength and skill. That rival is Kim Possible. Only Kim Possible can meet Shego blow for blow in combat, and only Kim Possible can push Shego to her limits and challenge her in ways no one else can. And damn if Shego doesn't love a challenge…
Four: Shego has fun with her Princess. Shego rarely finds herself pleased or entertained while under the employment of Dr. Drakken, despite her frequent sarcasm and frequent paid vacations. Shego only ever really smiles when Kimmie's around; it seems that just by showing up Kim Possible can bring a smile to Shego's face. And when the action starts? Please. Shego can't stop smiling then. The playful banter accentuated by daring kicks and swinging fists is always the highlight of Shego's day.
Five: Kimmie is adorable. She's still just a kid and the fact that she still sleeps with a stuffed animal and blushes when she's around a boy she likes just makes Shego want to hug her and never let go.
Six: Everything about Kim Possible is natural, from her hair to her toned figure. Shego is subconsciously obsessed with natural traits and is repulsed by falsehood and anything fabricated. That's why she hates clones. See, when Shego was younger she was dealt a lot of emotional damage by her peers for her green coloring and unique abilities, which were in fact given to her by a force of nature that, while extreme, was by no means "unnatural". She has since been forever sensitive to what is real and what is fake.
Seven: Shego is disgusted by the way people take advantage of Kim. She wants to smack some sense into that red head and teach her how to say "No". If it was anyone else choosing to devote every moment of their free time and then some to help someone that couldn't help themselves, she wouldn't care. Ron Stoppable is a perfect example, though he is a complete idiot and only follows Kimmie around like a desperate puppy because that's what he is; Shego couldn't care less how he chooses to spend his time outside of Drakken's many secret lairs. But when Shego had first found out just how many extracurriculars Kim was a part of at school on top of saving the world and being captain of the cheer squad, she'd wanted to go down to Middleton and kill everyone just so Kim could get a moment of peace.
Eight: Shego knows she loves Kim because she gets so unbelievably jealous of Ron Stoppable it's ridiculous. When the dynamic duo shows up she can't wait for Kimmie to send him away, so it's just the two of them. Honestly, the only reason she'd ever sided with him when he'd gotten a hold of Drakken's evil was that she'd hoped, somewhere in the back of her mind, that she could split the two of them up forever. She had the same plan when she'd tried to use the Time Monkey to take over the world. It's so obvious he's in love with her… and it pisses Shego off.
Nine: Everything related to Kim Possible just comes so easily to Shego. The banter, the fighting, predicting what Kimmie's next move will be or how she'll make her entrance… Shego does it all without even really thinking about it. In every romance novel Shego's ever read (maybe four), that's the kind of familiarity soul mates have. And hey, if it happens like that in all the books then maybe that's how it happens in the real world.
Ten: Kim Possible is not perfect. She has flaws, and Shego is all too happy to list them. She tends to forget things, spreads herself too thin, she lets herself be bullied, and she's far too idealistic for her own good. All are flaws the young teen possesses, and all are aspects of the world's redheaded savior that Shego adores. After all, how can someone love perfection?
Shego… do you always write in third person?
Dammit Kimmie! I told you not to read that!