1) If she can have kids... use whatever means necessary to achieve fatherhood and then hand her the baby (car) seat along with the keys to the VX. After stowing said child in back of VX repeatedly...she'll most likely "tap-out"...ring the bell...you win VX back!
2) If she cannot have kids...borrow some...and make sure baby (car) seats are required....see above (#1) for rest of plan.
3) Mention the owner's manual routine on flat tire management when the flat occurs on the rear (LSD)....then follow her to her destination (incognito) <-----check local stalking laws......and stage a flat tire scenario utilizing either rear tire....wait 'til she gets home (depending on whether or not she followed the guidance):
A: chastize her for not following owners manual guidelines
B: keep throwing it out there about what a bummer it was to shuffle those tires around...and wouldn't be nice not to have too...
OR
ummm not to thread jack....but could you explain the flat tire management?