A niece is read as the next generation and what you pass on to it. Tradition links her to playfulness, care and the wish to be a positive influence.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.