my girlfriend never wanted to try wakeboarding and went straight to wakeskating. She got a 38" Original Wakeskate (local custom company). It is small enough for her to control, and the weight of it since it is an all wood concave deck helps it ride smooth and is more forgiving. The board is blank and is just a dark stained wood which you cant go wrong with.
She has ridden my 38" Integrity, and she definitely prefers the all wood board over it because it isnt as responsive.
She has also tried a Flat deck and cant ride them well. The lack of concave makes it harder for her to edge around.
For your girl friend I would recommend the Water Monsters 39.5"
. They are only $250 for a really solid board(made in the USA by the Pastura brothers!), and the shape is awesome. You could also ride it too.