There are many reasons a person might be given a few lottery tickets. They might be stocking stuffers, or small birthday gifts or housewarming gifts, etc.
The ticket belongs to the recipient. That is clear.
But if it wins big is there a traditional split ratio? Does the recipient keep it all? Split it 50–50? Kick back 10%? Or give nothing?

What would you do if a ticket someone gave you won $10,000?
What would you do if it won $1,000,000?

Does this vary by culture?

A few years ago I went to a large bachelor party for an the son of a very Italian friend. They had a “50–50 raffle” where everyone buys tickets and one ticket is drawn from a jar. The winner gets half the pot and the future groom gets the other half.
However, the tacit agreement in their circle is the winner collects his winnings and gives it all to the groom.
(I’m glad I was not the winner. That would have been embarrassing.)