Why does Amy write a will?

From the text:

In her first effort at being very, very good, she decided to make her will, as Aunt March had done, so that if she did fall ill and die, her possessions might be justly and generously divided.

We can see that all the characters are developed except for Amy

she tries to show the other people that she is mature and writes a will

this also shows her ladylike personality and her approach towards things