you might want to try placing some double-sided tape on the gate, where she climbs it. the double-sided tape is a harmless way of deterring her from climbing on top of it. the double-sided tape will be a strange, but harmless, sensation to her paws which will hopefully keep her from continuing to climb the gate. you can find some thick double-sided tape at an arts & crafts store, or office supply store. the kind i am talking about is usually used for affixing address numbers to one's home so it is strong enough to last a while.
another alternative is available at most franchised pet stores. it is a mouse-trap like device that is harmless to dogs because it uses a large, plastic, spatula-like flap to gently startle the dog when it is set off. you set it like a mouse trap and it is very sensitive to movement. if you were to place on the top of the gate, or near the gate, it might help deter your dog from using it as a ladder.
perhaps those might help to get you started.
another option is to teach her the "off" command and reinforce that when you see her climb or want to climb the gate. since she is young, it is a great time to teach her what she can and cannot do in your home.
a big part of training the "off" command will be to catch her in the act. in order to do so, try attaching a bell to the gate, that way you will "hear her" as she starts to make her escape.
good luck.