I work with babies under 1, even they can point to pictures to “ask” me to name them. Knowing others know stuff is basic.
Theory of Mind isnt something we use in my field, but from a quick glance it’s knowing other people have minds, that they have their own desires, feelings, thoughts, etc not that they know information.
In ECEC terms we would think of that as the end of their egocentric stage. Usually seen around 1-3.