The second biggest thing in her growth is that Beth has scarlet. After Mrs. March goes to look after Mr. March, the sisters (except Beth) go back to the idle state of life. It is Beth that does all the little duties to make things right. She does not forget that her mother asks them to go and see the Hummels. As one of the Hummels’ babies is sick, Beth doesn't know what to do and hopes someone to go with her. Jo and Meg promise to go but they both make excuses not to go. It is Beth that goes alone. Unfortunately, the baby is dead and she gets scarlet, which makes Jo very guilty. She thinks if she went to the Hummels, Beth might not get scarlet. Realizing her selfishness, she is so remorseful and determines to get rid of her selfishness. Fortunately, though Beth is a little weak, she is recovering from scarlet, under the care of Jo. After that Jo indeed overcomes her selfishness. Once, in order to make Beth healthier, she spends all her contribution on Beth’s tip to seaside.
The last thing is that she and Mr. Bhaer get married. Getting acquaintance with Mr. Bhaer, she learns not only a lot of knowledge, but also modesty, kindness, and lofty character from him. It makes it clear for her to set up the right outlook on life. After Beth dies, Meg has children, and Amy and Laurie marry happily, Jo rethinks about her life and changes her idea on love. She believes that Mr. Bhaer is the one she appreciates and shares her life with. It is him that makes Jo changes her mind on being single all her life. Besides, she and Mr. Bhaer set up a school for boys, which makes her realize her own value and keep her independence as a lady. Despite of hard work, much anxiety, and a perpetual racket, Jo is a happy woman with her boys at school. “She enjoys it heartily and finds the applause of her boys more satisfying than any praise of the world.” (Louisa May Alcott 451)
Although her castle is so different from the past, the ending is good. She has a happy family of her own with a learned professor and a lovely son. Besides, the couple owns their own career and lives a happy life, though they are not rich.

Ⅲ. The oldest Sister—Meg and little Angel—Beth

“Being plump and fair, Meg, the eldest of the four, is very pretty, with large eyes, plenty of soft and brown hair, a sweet mouth, and white hands she is proud of.” (Louisa May Alcott 6) With a shy manner, a timid voice, and a peaceful expression, Beth is a rosy, smooth—haired, bright—eyed girl. She is called “Little Tranquility”.
3.1 Meg’s and Beth’s characteristics and outlooks on life
    Meg is a tender, traditional, lovely, and beautiful girl. Being independent, she works as a private teacher to support the family. Having a sweet voice like a flute, she and her mother lead a family choir, which makes the house cheerful. As the oldest sister, she is always taking care of her sisters. However, Meg has a little vanity. “She loves beautiful things and hopes to lead a luxurious life. She would like a lovely house filled with all sorts of luxurious things—nice food, pretty clothes, handsome furniture, pleasant people, plenty of servants and lots of money.” (Louisa May Alcott 133) Without working a bit, she is to be the mistress of it, and manage it as she liked. Besides, she would also do something good and make others love her dearly. This is her castle in the air.
Being kind, gentle, obedient, hardworking and unselfish, Beth is called the little angel. “She lives for others so cheerful that no one sees the sacrifices till the sweet, sunshiny presence vanish, leaving silence and shadow behind.”(Louisa May Alcott 38) So deeply she loves music that she practices away so patiently at the old instrument. She is too shy to go to school and does her lesson at home with her father. Enough is as good as a feast. So Beth is a happy girl who is easily contented. She does not long for that much as her sisters. Since she has got a little piano from Mr. Laurence, all that she wants is to stayed at home safe with Father and Mother, and help take care of the family. This was her castle in the air. 《小妇人》中女性形象的分析(5):http://www.youerw.com/yingyu/lunwen_7450.html