Rose in Bloom by Louisa May Alcott

Uncle Alec did not object and, finding that no one had any claim upon the child, permitted Rose to keep it for a time at least. So little Dulce, newly equipped even to a name, took her place among them and slowly began to thrive. But she did not grow pretty and never was a gay, attractive child, for she seemed to have been born in sorrow and brought up in misery. A pale, pensive little creature, always creeping into corners and looking timidly out, as if asking leave to live, and, when offered playthings, taking them with a meek surprise that was very touching.

Rose soon won her heart, and then almost wished she had not, for baby clung to her with inconvenient fondness, changing her former wail of "Marmar" into a lament for "Aunty Wose" if separated long. Nevertheless, there was great satisfaction in cherishing the little waif, for she learned more than she could teach and felt a sense of responsibility which was excellent ballast for her enthusiastic nature.