Princess Christina does not have tiara in her personal collection anymore, since the one she had was stolen.
But, except for tiaras, she has a nice collection of jewels: necklaces, brooches... Not a huge collection, but a nice one anyway!
She owns several jewels of sapphires and diamonds:
She regularly wears an impressive diamond choker with a large, garland-style diamond clasp at the front (possibly bearing the monogram "O2", for King Oskar II?):
The clasp of this choker was formerly worn as a brooch:
Unfortunately, I have no information about the origins of these jewels, and I do not remember having seen them on other Swedish royal ladies before Princess Christina. Some of them look of antique style, other look more modern, but I have no clue about the origin.