>>3253562Extrapolating upon what we know:
A civilian Tanya unfairly uses knowledge of future technology and business patterns to earn like a billion-trillion Bisondollars and worldwide respect, or at least some kind of peace prize. She marries into a royal family and gains regional influence to match her money.
At some point, Tanya either invents or participates in magic bloodsport and loses a limb, par for the course when everyone keeps fucking exploding each other. As a public figure in peacetime, this sparks a huge scandal and places scrutiny on mages. Her position of power has little effect on rising anti-mage sentiment.
Alternate dimension WW2 does not happen in earnest until Alternate August 1997, manifesting during the 30's as a series of border skirmishes, brittle treaties, and asshole trade deals. Middling art-school student Schmadolf Schmittler flunks out, blames mages, joins a literary club, and writes anti-wizard slam poetry until he gets over his issues.
In her final years, sweet old Tanya Degurechaff spends her time tending a beautiful garden, to stave off recurring hallucinations of oncoming trains. Neighborhood children like to help her water the flowers. On her 61st birthday, she chokes to death on a walnut when her prosthetic arm suddenly malfunctions despite excellent maintenance.
As per her will, the garden remains exactly the same for decades, and draws in above-average tourism to keep her estate afloat. It's a nice place to visit.
(Muggles burn it down in 2003.)