She's talkative to a fault-- people usually tire of her fairly quickly, though she doesn't seem to get the point at all. She'll keep talking and talking and talking until someone is blatant with her, and then the poor girl gets her feelings hurt. This cycle can be quite annoying for potential friends, but she is a wonderful friend when it comes down to it. She's willing to take a bullet for just about anyone who is nice to her, honestly, as she's just that kind. She values anyone and everyone, and is far too trusting for her own good. She's always able to pinpoint something good in everyone, and as such can befriend some of the most irritating of people.
It goes without saying that she's extremely optimistic. She isn't easy to anger, either; she's more likely to blame situations on herself than anyone else. It's easy for her to see the other person's side of the argument, and as such, she's a bit of a doormat like her sister. That's okay with her, though; unlike her sister, she doesn't let it bring her down. She doesn't have many self-esteem issues at all, actually-- she's just too optimistic for it.
She's a ball of energy, too, in that she absolutely cannot stop moving for any length of time-- people often wonder if ever sleeps, though those close to her know that she is a very deep sleeper. Anyone who dares bother her when she's sleeping like this knows that this is the only time her anger is triggered-- and then she can become almost violent. So just don't wake her up or bother her when she's sleepy, trust me.
Sparrow is painfully childish, to the point that it's hard to explain adult concepts to her. When presented with difficult situations, she'll give advice that seems rather easy in nature, but it's very naive. It's not "that" easy, and she doesn't seem to understand that. Really difficult situations just confuse her, really, to the point that she seems to go on some sort of brain overload. She's a good listener, though, and she truly cares about others.
She's really a child at heart-- her room is full of stuffed animals, and it seems like you've just walked into a ten year old's room. She seems to fangirl over silly things, too, and practically "ship" her friends with each other. It's a little goofy. By the same token, however, she has no idea how to handle romance on her own, so she prefers not to think about it. Being in a relationship would confuse her to no end.