I gave a land deed to my lawyer to transfer the deed to my sister’s name through an affidavit of heirship. Is the original land deed kept by the lawyer?

The original deed must be filed with the County Clerk to be effective. In most counties now, the clerk scans the deed and immediately returns the original to the filer. In other counties, the deed is recorded and eventually returned to the filer. You can request the original from the attorney, But you should confirm that is recorded, which is indicated by filing stamps or other notations on the original. If it is not filed, see to it that is filed.