This answer provides a new /gtr/database key persdata that accepts predefined choices like JaneID. When persdata=JaneID is used, the corresponding key-value list stored in that style is retrieved.
Disclaimer: this is in Metapost but it's not really a proper answer to the question.
It is, of course, possible to draw anything nicely with Metapost, such as this version of your tree:
but as you can see below, I did not do that using a qtree-like syntax. Whether you think this is "easy" is a matter of opinion, experience, number of trees you ...