Meaning: This means that the girl is unable to find her most-loved doll.
Choice of Words: Lost means that she is unable to find her doll. Favorite means that it is her most-loved doll.
Alternative Expressions
The young lady misplaced her cherished plaything.
Meaning: This sentence also tells us that the girl can't find her doll, which is special to her.
Choice of Words: This sentence uses more formal words that an 8-year-old may not be familiar with. The word "misplaced" means that the girl can't find her doll. The word "cherished" means that the doll is special to the girl. The word "plaything" is a more formal way to say "doll."
The wee lass hath lost her beloved dolly.
Meaning: This sentence also tells us that the girl can't find her doll, which is special to her.
Choice of Words: This sentence uses archaic language that an 8-year-old is unlikely to understand. The word "wee" means small. The word "lass" means girl. The word "hath" is an old-fashioned way to say "has." The word "lost" means that the girl can't find her doll. The word "beloved" means that the doll is special to the girl. The word "dolly" is a more formal way to say "doll."