Posting a state and county would be helpful so forum owners from the area can help you find that data.
The first thing you can do is contact the Division Order analyst for Endeavor and ask for a copy of the paragraph of the title opinion that pertains to your wife. Tell them that you have no record of ownership and need to update your files. They have done an extensive title search and ascertained that she is an owner. However, sometimes they are wrong, so it is good to get a copy of the record and see if the names ring a bell. You can also ask Endeavor for a copy of the lease that pertains to that well. They should have it or can give you the book and page number where it is filed so you can pull up a copy (digital files only go back so far, so that is why you ask for a copy from them.) Ask the DO analyst for your “net acres”. Once you get that information, you may want to do a search on unclaimed funds and see if the state is holding any other funds for her based upon that ancestor.