Well you need to teach her at first on the lead..
My pup is exactly the same so when he has a toy near me I take hold of it and ask him 'drop'. At first he held on but I prised it out his mouth and gave him a treat and lots of fuss, now if I ask hiom to drop he will drop it and run over quick for a treat and some fuss

You can teach 'leave too' have something your pup likes in your hand and ask him to leave, if he tries to take it, clost your hand. If when you say 'leave' he makes no move to take it, treat him from the other hand with something else. Then when you see your pup about to pick something up and say leave, he will. It won't happen overnight, but just practice

xx

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