I did a 30 day notice and a three day notice to evict. Went to court and they dismissed my case saying that I needed to give her four months. Ohio

I am the executor of my mothers estate. My niece was living with her and still is in the house while we went through the probate process. I have a buyer for the house but she won’t leave. I served her a 30 day notice to vacate. And the 31st day I sent her a three day notice to vacate. On the fourth day I filed with the court. I had my court date and the Magistrate dismissed my case completely saying that I did not give enough time. That she was a tenant and she is supposedly getting four months to vacate. And since I failed to soon he dismissed everything. I thought I did everything right.