Humphrey has tried earn the $4,900 for the 23-day trip, but is short about $2,500 for the trip to Australia on June 24.
She filled out the paperwork for a $5,000 bank loan earlier this week, but did not immediately turn it in.
As a student ambassador, she would explain how the United States government works to Australia and New Zealand students and adults in exchange for learning about them. The program's ultimate goal is to aid world peace.
Humphrey also would have a chance to earn college credits and scholarships on the trip.
If she goes, she will explore national landmarks, meet foreign leaders and temporarily live with a host family to learn more about the country and culture.
She has asked local businesses for funds in the past several months but has been unsuccessful. She said most seemed to feel that if they offer her money, they'd have to give money to everyone.
Her mother, Michelle Vining, held a pig roast fund-raiser with a live bluegrass band May 13, but it rained, only 22 people showed and the event did not break even.
"When this thing went wrong (my mother) cried for hours because she really wants me to go," said Humphrey, who plans to attend Shippensburg University in the fall and would like to be a pediatrician.
"I guess in the end, I know everything's going to turn out all right with my life, even if I don't get everything I want. Nobody gets everything they want," she said.
Vining said her daughter will be hurt if she can't be one of the 15 people from Maryland, West Virginia and Pennsylvania to go on the trip , but she knows Humphrey will be strong.
"My daughter is one of the most confident people I know," Vining said. "Don't tell her she's not going to do it. She's going to do it if it's possible. I told her this is near impossible and she said, 'Mom, I'm not going to give up until the end.'"
If Humphrey can't go, she said she will survive, just like her mother would.
"When times are rough, she's really been strong though it all," Humphrey said. "I think I get a lot of that from her."