Easy option is a replacement wife.
Adjustable pedals would be tricky & expensive to fit, but you may be able to get some extensions fabricated - like blocks on your bike pedals. These would need to be bolted in place, so not a five minute job to fit, and the insurance company would need to be told.
What about big platform shoes??? - hardly safe though.
I don't think that lifting the seat will help, unless she drives in a very reclined position.
I don't think there's an easy solution to this.
