return to school.

Mami is not pleased to have a dog.  She considers the dog trouble, and is worried that the family will not get the visas they need to get out of the country.  She thinks the dog is just a worthless token gesture—a consolation prize.  Her mother is sort of right.

He ate all of Mami’s orchids, and that little hyperactive baton of a tail knocked things off the low coffee table whenever Liberty climbed on the couch to leave his footprints in among the flower prints. He tore up Mami’s garden looking for buried treasure.

They name the dog Liberty out of a hope for the future anyway.  To the little girl, he is just a fun puppy.  She does not really understand how much her mother is afraid, and how badly the family needs to get out.  Her mother’s hopes for the future are not as meaningful to her.  Papa forgives the dog, saying it does not understand Spanish.  He is so hopeful for the future that he doesn’t care.  To him, the dog represents that hope.

Things get real for the narrator when she sees two men in sunglasses sneaking around her house.  They frighten her, grabbing Liberty.  They make her promise that she hasn’t seen them.  The next thing she knows, “Mister Victor” from the embassy comes to look in on them, and when he isn’t there he has someone from the embassy there to “keep an eye on them.”  It was no longer safe in the house to talk about certain things, because the house is bugged.  The narrator realizes they are planning their escape.

The image of the two men in mirror glasses flashed through my head. So as not to think about them, I put my arm around Liberty and buried my face in his neck.

She understands that she will have to leave her dog.  The dog cannot go with them to the United States, so she has to choose between her family, and her puppy.  It’s a difficult choice for a little girl to make, but sometimes even a little girl has to choose.

Growing up is difficult to do.  A war makes growing up much faster.  The narrator of this story is having to deal with her country's war, and the loss that comes with it.  She will face many changes ahead, but the first one was the change of realizing she had grown up enough to leave behind the dog she loved to give her family a future.

You have given an interesting list of options above. If I were you, I would have to say that out of those options, loving and curious is the most likely. This is because all the others are too extreme and do not accurately describe the narrator. Certainly she is something of a "tomboy" by her own account, but she is definitely not sneaky and wild, as you put it. We can say that the narrator is curious by the way that she is always watching and paying attention to the changes that are going on around her, and how she picks up that something is going on and that all is not well. Then we can argue that she is loving through the way in which she develops a very close bond with Liberty, the dog that she is given and needs to leave behind in order to paradoxically gain liberty. Because she knows her dog is in danger if he stays, she has to scare him away, and out of love for him, has to be violent towards him:

Finally I have to resort to Mami's techniques. I kick him, softly at first, but then, when he keeps tagging behind me, I kick him hard. He whimpers and dashes away toward the front yard, disappearing in areas of darkness, then reappearing when he passes through lighted areas.

We can see the profound love that the narrator has for her dog expressed in the violence that she has to enact upon Liberty.

The reader is not given anything concrete in terms of the narrator's appearance.  There are intimations given as to how she looks, but overall, there is nothing absolute in terms of appearance description. One articulation about the narrator's appearance is that she is "the tomboy" of the children:  

I had always been the tomboy, the live wire, the troublemaker, the one who was going to drive Mami to drink, the one she was going to give away to the Haitians. While the sisters dressed pretty and stayed clean in the playroom, I was out roaming the world looking for trouble. 

Such a detail enables the reader to fully grasp why the narrator and Liberty share such a bond.  Like Liberty, she enjoys being out in the world and doing what her mother would consider abhorrent. Continuing this description of a tomboy, the narrator details how she takes advantage of her mother's distracted state to not "take a bath" and that she was able to enjoy Coca- Cola instead of her usual boiled milk with beaten egg meal. The narrator is a typical adolescent who enjoys getting into trouble and, like Liberty, instigating the rage within her mother.