There is case law on this. Unless they had a written contract to share that particular ticket, or all tickets, she gets to keep it all for herself.
That's not how it went down in a NJ court two weeks ago.
All tickets are time stamped as to the sale. If the ticket was bought in a group with 4 other tickets shortly after the manager gave her the 5 dollars, this woman is toast.
If the woman bought a ticket time stamped before the manager gave her the money, she gets it all.
All the rest of the pool tickets were in the office safe.
I think you have it backwards.