I'd ask her to live in dreams, as reality is unknowingly cruel. And perhaps her dream is to fly in the welkin of the soft whisper of her hid desires. and reality is world around her. and so I wanna her to become Joan of Arc. Happy Daughters' Day! Being a writer means being able to explore all sorts of possibilities. So use #DearDaughter and imagine having one. If you already have one then write to her. BTW I recommend watching Sarah Kay's spoken word poem, "If I should have a daughter."