My wife needs advice...please.

[Elizabeth]

Not knowing your wife's age or where she intends to wear the skirt it is hard to say. Me being in my mid fifties prefer a few inches above my knees, which I feel is short enough to be nice looking on someone my age but not what I consider "doughty or frumpy". Plus that length I feel decently covered and not having to worry about my every move. I feel this length is fine for out and about and to festivals. If I was going to have a skirt for more "formal events" I would tend to go a little longer to the top of the knee or sightly below the knee cap. But as I said that is my age and stage and what I am comfortable with.