Apparently the sherrif was suggesting that he thought you should pursue the case in civil court by filing law suit. Depending on how much the item is worth determines which court to sue in. Small claims court may bhe a possibility.
Any response given is not to be taken as legal advice or to create an attorney client relationship.
I bet your friend has a different version of the story. Something like, You gave me this "item" and now you're trying to get it back. Seems like a silly thing but its actually one of the oldest problems and may be the genesis of the old saying that "possession is nine tenths of the law." If you did "take her to court" how will you prove your case, that is, that she "stole" it from you? Alternatively, how will you disprove her case, that is that you "gave it to her?" What evidence do you have? It's a more interesting little problem than it appears because just on its face, it's a classic he said, she said, so how does the court decide it? Are you prepared to answer the question why did you let your friend "hold" it? If I was the judge that would be my first question. Another question is what is the value of the "item?" Is it worth the trouble? Only you can decide that.