An heir is read as being next in line for a role, a tradition or an expectation. Dream books link it to pressure to continue what others began, and to whether you want to.
Does the traditional reading fit your dream, or did it mean something else to you?
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.