What happened to the widow's jar of flour and jug of oil?

Answer: They never ran out

The jar of flour was not used up and the jug of oil did not run dry, as the Lord had spoken through Elijah.

“The jar of flour was not exhausted and the jug of oil did not run dry, according to the word that the LORD had spoken through Elijah.”— 1 Kings 17:16 (BSB)