What about short people? Seriously, short adults are at a disadvantage. Even with modern seatbelts that adjust up or down.
My 5 foot wife makes do by lapping the top shoulder portion under her arm.
They have all sorts of gismos to help with the problem.
You are too cheap to spring for less than $10 to ensure her safety?
https://www.amazon.com/s?k=seatbelt+adjuster&ref=nb_sb_noss_1
I use the “M” design, I even bring one with me when riding in another’s vehicle.