“Portrait of a girl with a comic book” Poetry help!?

My moms birthday is coming up, and she is really into poetry

her favorite poem is “portrait of a girl with a comic book”

For her Birthday i wanted to analyze the poem and frame it,

thing it, i dont know where to start,

i dont even know what the poem is about!

any help would be great

thanks so much!

Thirteen’s no age at all. Thirteen is nothing.

It is not wit, or powder on the face,

Or Wenesday matinee, or misses’ clothing,

Or intellect, or grace.

Twelve has its tribal customs. But thirteen

Is neither boys in battered cars nor dolls.

Not Sara Crewe or movie magazine,

Or pennants on the walls.

Thirteen keeps diaries and tropical fish

(A month, at most); scorns jumpropes in the spring;

Could not, would fortune grant it, name its wish;

Wants nothing, everything;

Has secrets from itself, friends it despises;

Admits none or the terrors that it feels;

Own half a hundred masks but no disguises;

And walks upon its heels.

Thirteen’s anomalous – not that, not this:

Not folded bud, or wave that laps a shore,

Or moth proverbial from the chrysalis.

Is the one age defeats the metaphor.

Is not a town, like childhood, strongly walled

But easily surrounded, in no city.

Nor, quitted once, can it be quite recalled –

Not even with pity.