Source: The Great Interpretation of Dreams (Ibn Sirin)
A niece (brother's daughter) in a dream indicates relief, joy, and approaching goodness.
Source: Perfuming Humanity in the Expression of Dreams (Al-Nabulsi)
A niece (brother's daughter) indicates a world approaching with goodness. Seeing her indicates the end of worry.
Source: Signs in the Science of Expressions (Ibn Shaheen)
A niece (brother's daughter) is interpreted as goodness and joy. Whoever sees her will attain goodness.