I have similar to a reward system but each thing has a money amount to it.

Make bed 50c
Put dishes on sink 50c
Wash dishes $1

There is a whole ot of things she can do for $1, $2, $5 or for smaller amounts.

I use play money. You can get Australian play money from the cheap shops for $2 a set, and a cheap wallet just for that. Each week there are rewards that cost money. Going to the park is $5, having a full morning/afternoon at the park with a picnic is $10. Movie nights at home is $5 (usually a suitable movie comes on tv on friday or saturday). Having a friend over for a play is $2, having a friend sleep over is $10. She pays with play money of course and she can spend it or save it.