Boxes, Sherlock Holmes (Ritchie), Irene Adler/Mary Morstan
Irene starts sending boxes to Mary. Just small things she finds on her travels, jewelry sometimes, but most often a pretty shell, or some trinket she's found at a market stall. She doesn't think too much of it, she just wants Mary to have those things.
When she comes to visit Mary next she finds a large chest filled with all her boxes.