As you can see and hear, her verbal skills are quite advanced. "Peek-a-boo" clear as day.
Also, if you have impressionable sons -- you may choose to not let them watch the clip. Julia is in her napping outfit which is somewhat immodest (although her shoulders are fully covered).
To see Sebastian's version of peek-a-boo ... click here.
(and as an important FYI -- those gorgeous flower hanger things on the door came with the house -- my taste isn't quite as sophisticated)