Where Does Rex get the money to send Jeannette to college?

The summer before Jeannette's last year of college in New York she is talking to her dad on the phone and mentions that she will not go back for her last year of college because she is still short $1000 for tuition that year even though she had worked all summer to earn the money. Rex says why didn't you tell me sooner and then proceeds to show up at Jeanettes door a week later with $950 and an item that she could pawn for $50. Where does the reader inferr that Rex got the money. Did he steal it? Did he borrow it? Did he take out a loan from the bank? Did he have money all along and just not want to use it for himself? Where did Rex get the money?