Symbolism, Imagery, Allegory
One of the greatest gifts Granddaddy Opal gives Miracle is her bicycle, which she names Etain, after a character in an Irish legend. His approach to giving a bicycle as a gift, though, is a bit different from how society typically approaches it: Granddaddy Opal's a firm believer in getting old bikes and fixing them up like new. As he explains to Miracle:
"You fix it up, paint, and then it's yours […] You take care of it, grease it up good every now and then, give it a name, and you ride it everywhere. You and that bicycle become best friends. It's a real special relationship." (6.7)
It's all of this for Miracle, but it's also something more: independence. Miracle's pretty much grown up under Gigi's thumb, surrounded by rules about what colors to wear and what numbers to avoid—having her own bike is one of the first experiences she ever has with being able to care for something on her own and travel places by herself. It's also an activity that requires her to take off Dane's bathrobe. While she frequently wears the sash tied around her waist, she still has to rid herself of the robe's bulk in order to enjoy the bike. (For more on the robe, be sure to check out its page elsewhere in this section.)
The story behind the bike's name is also pretty interesting. According to the story of Etain, Etain was a beautiful woman who was turned into a butterfly by another lady who was jealous of her, then blown away from home in a magic storm. Etain manages to find happiness in a new location, even as a butterfly, but this other woman can't stand the idea of her being content, so she sends another storm and blows her somewhere else. She even makes another lady drink the butterfly, and that woman eventually gives birth to Etain, returning her to human form (6.34).
Hold on a minute. This is a really weird story, right? But it bears a strong resemblance to Miracle's situation if we think about it: She's transformed into something inhuman through Gigi's superstitions and obsession with her mom's death, and is blown from place to place by literal and figurative storms. Miracle even gives a reference at the end of the book to feeling reborn:
I had never really noticed people before, and I wondered what it meant, to see them now, as if they were newly born upon this earth, and I, too, newly born, alive, truly alive. (30.1)
As a result of all of this, Miracle, just like Etain, becomes human again as she accepts the truth about her mother's death and her family. Could it also be that Gigi is in some way jealous of Miracle, hence the limitations she places on her? Not all of this analogy is clear-cut, but it definitely makes sense. And one thing's for certain: Etain the bicycle gives Miracle an important taste of freedom.