My Benjamin and Jane (Stitt) Smith moved from PA to Brown Co. IN. Benjamin's mother was Catharine Gooden. I do not know her parents' names.
Benjamin, Jane, their baby John, and Catharine were in Loyalhanna, Westmoreland Co., PA in the 1850 census. They married in Armstrong Co. PA.
I do not know if this information will help you or complicate your search.
Have you looked for court records in Brown Co.? They might cover this orphan case.
Also, you might post a message to the INBROWN-L list to see if someone has an index to the cemetery book. There are nice people on that list who will do lookups if you ask. Without a given name, they might not, but you never know.
Of course, if your orphans came from some other county or state, that wouldn't help you. But the court records still would.
If no one has a court index, you might try the http://www.familysearch.orghttp://www.familysearch.org (Jesus Christ of Latter Day Saints) website to see if they have microfilm you and look at at an LDS site near you.
You've probably already done all these things, but just in case you haven't I thought I mention it.