Bleeding history? Doctors would typically order a test for VWD if the patient had a history of abnormal bruising and/or bleeding that made them suspicious, especially if there was a similar history among other members of the family. You don't mention how old your step-daughter is; the question is probably best directed to your daughter if she is an adult, or to her doctor if she is a child.
Bleeding. A physician thinks for some reason that your step-daughter has shown an unusual tendency to bleed, or one of her relatives is known to have von-willebrand's. The harder you look, the more vw's you find; some say 1 person in 100 has a mild version. It's good to know, usually not a big deal.