Dulong is Anja's business partner so IMO they give Mary the jewellery for free to promote the newest lines and when they inroduce a new collection she passes them on to others.
That's exactly what I've been thinking! She probably gets everything designed by Dulong for free so it's not really such a big deal if she gives some pieces to others. She'd probably do the same if she was taking jewellery from Ole Lynggaard for free, which is highly unlikely it happens!!
Anyway, she has sooo much jewellery. When does she even wear all these earrings, necklaces, rings, brooches etc.?
She definitely has so many clothes and accessories she never wears. Why not do a nice thing and, if she's as popular as she and her PR team think she is, auction some pieces and donate the funds raised to charity??