Yes, the acceleration setting simply affects how quickly the motor speeds up.
If you set it too low, you will not have instant power when you occasionally need it to quickly overtake or pull away on steep hills.
You'll have to try reducing it and see what it's like, but you may have to increase it again if you find it is making it too unpleasant to ride.
If both bikes have the same diameter wheels and you want to have a faster top speed than your wife you may have to reduce her
FWD Speed Scale, but don't forget to also set her
Acceleration setting slower than yours or she will leave you behind every time you have to pull away from a standstill.
If you have done all of this and find that you are still unable to keep up with her, you may have to gradually decrease her
Max Current settings until you can keep up.
Alan