Who is Lady Titania, from "A Midsummer Night's Dream" from The Sandman and what is their importance?

Lady Titania is the fairy queen who comes to see Shakespeare's play, in which she is a character. The Sandman has invited Lady Titania to the performance, and she is curious about his motives. She enjoys the play, and she is taken with Shakespeare's young son, Hamnet. Lady Titania tells Hamnet all about the joys of the fairy world, likely attempting to lure him back with her. Hamnet dies at a young age, perhaps an indication that he comes to Lady Titania's fairy world after all.