Should I preemptively turn myself in to get reduced charges?

Several months ago, I found an iPhone. It was locked. I brought it home and it sat for months, no calls made to it or anything. No one was trying to get it back. Last week, I started having money problems and I remembered this iPhone I happen to have. I decide to reset it to factory settings, list it on Craigslist and try to make some money. A woman agrees to buy it, we meet, she pays me and we go our separate ways. A few hours later, she texts me and tells me it was stolen and she is going to give my info to the police. I text her back to arrange to give her the money back and to go with her to the police to explain what happened in full. She ignores me. Should I just go to the two precincts/departments I think she may contact and preemptively get ahead of this? The last thing I want is to be charged with selling stolen goods. I thought it was abandoned/forgotten. If I am proactive, will that help my situation?