I am especially since she says that she does not care and I have to pay for any replacement and that I should not have let it get washed.
I use Nikwax TX Direct to revive or replenish the DWR coating. They come in wash-in or spray-on. Which one will work depends on the kind of tech fabric you have.
You can find this stuff at REI/MEC/Outdoor stores.
Also get Nikwax Tech wash for future washes.