The auction started last night with a reserve of $1500, and has already drawn some interesting suggestions, ranging from Indian actresses to President Barack Obama.
"As long as it's not rude or offensive, we won't say no to anything," said Lynda, 19, who, like her sister, was not given a middle name at birth.
The young women have targeted companies and used social media in the hope of getting as much money as possible to fund a campervan trip around the South Island for Molly, who was born there.
The sisters have both been friends with Molly for nearly five years and said that while she was going through a range of emotions, Molly has told them she is overwhelmed with their generous offer and thinks the idea is "really cool."
Their TradeMe auction can be found here.