In perceiving the world, vy tends to avoid thinking of behaviors, objects, and so on in either/or terms. so, she does not describe a person as "young" or "old," but as "not so young," "a little bit old," and "not so old." vy is operating from what kind of a worldview?

I believe the answer is relational worldview
Relational Worldview refers to a certain collective thought which tend to view that there is no such thing as a definitive term.
Take the term 'old' and 'young' for example. In the past, the life expectancy of average people was really low. So the term 'old' often used to describe someone in their 40s. In current year, the term 'old' usually used for someone in their 60s or above.