Keep something interesting to her on you at all times since you never know when this will happen. A toy, a treat in your pocket, something that she likes. Then bribe her. lol You have something better then her & she will want it. lol

Tell her once to drop the item, the second time you tell her show her what you have. Try your hardest not to say the command drop more than two times then she will catch on that she doesn't have to drop the item until the 10th time you say it. You'll pretty much be back to square one. lol

In the meantime set aside a few minutes each day working on the drop command. Practice with one of her toys. And remember to always praise.

Pretty soon you'll say drop it once & she will drop what ever she has even if you have nthing to offer her. But remember training never stops, even after she learns the command really well always remember to praise her when ever possible, even if it's just a simple pat on the head.