I'm not sure why you need to know how many lines and how many syllables are in each line of the poem, but the answer is 15 lines, and you can count the syllables.
The tone of the poem is joyous. The poet accepts the fact that she has big hips, and she celebrates her body. She loves herself just the way she is. Interestingly, almost in contrast to the size of her hips, the words she uses to describe them are rather short: big, free, mighty, magic. She also refrains from capitalizing any words, almost as if they can't compete with her big hips.
She personifies her hips by giving them a mind of their own: "they don't like to be held back" and "they go where they want to go."
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