if findagrave doesnt list a title for a name there is usually a reason that option is not given. the Following is an example The Honourable or The Honorable (abbreviated to The Hon., Hon. or formerly The Hon'ble—the latter term is still used in South Asia) is a style that is used before the names of certain classes of people. It is considered to be an honorific styling, and it is only used for living people.
Another example is MR. Or Mrs they're normally only used with living people. We might say Mrs Darwin if we meant Darwin's wife and didn't know what her name was.
Findagrave does allow the use of Mrs which would indicate the sex of the person such as Robert SMith versus MRS ROBERT SMITH Please dont enter titles in the name field as it makes that person hard to find. Title should only be used in title field and not in the name field. Very few people would search for MR______.