Sansa is Queen in the North while Jon is banished to serve the Night's Watch for the rest of his life. And yet, Sansa can't just accept that Jon can never come home again, that he will never be able to answer the feelings she has for him, that she will have to marry someone else to let him father the future heirs of the North. And so she sends ravens. Ravens to Jon to tell him how much she misses him. And ravens to Bran to ask him when it is safe to end Jon's punishment and bring him back to Winterfell.