I'm wondering what kind of side effects or Red Court tendencies Maggie might have been born with. She obviously doesn't have the blood thirst, but that doesn't mean she couldn't have inherited some other interesting or even disturbing Red Court traits.
Just to think about fringe possibilities, I don't think it's impossible that when Maggie reaches puberty, the first time she kisses someone she finds out her kiss; saliva actually, acts as a mild narcotic on the person she kisses. Not as strong as the Red Court; and probably not as strong as her mother, but strong enough to be both useful but at times annoying; like when she doesn't want the other party to get stoned, so to speak.
Another possibility is sudden super-strength; when in danger. It would be useful those times when Mouse isn't present or is present but has his paws full. In a half-turned vampire like Susan, that kind of activity would increase her blood thirst and could potentially lead to a loss of control. Seeing as Maggie isn't a half-turned vampire, use of super-strength might have other downsides. It might make her ability to control her emotions; meaning control her magic, more unstable. Assuming the White Council exists when Maggie becomes an adult, there will have to be a reason for them to be afraid of her, besides her family history. Another possibility is that use of super-strength temporarily diminishes Maggie's ability to use magic, or at least use complex magic.
I'm somewhat stuck after that. I don't remember what other traits that Red Court vampires had that might transfer to a human hybrid. Wait, there is one. If I really want to go outside the box, when her magic comes in I could see Maggie becoming able to form a kind of flesh mask, making her into a pseudo shape shifter, but possibly only good for mimicking other humans or those beings who look human. One problem Maggie would have is that her flesh mask recreation of another person would only be as good as her memory would allow it to be. She couldn't do something down to retinas like Goodman Grey. Plus, I don't think a flesh mask would necessarily allow her to copy someone else's voice.
Anyone have any different ideas?