Little Daryl-Ann, who is 2 years and 3 months old, suffers from severe cerebral palsy, microcephaly and polymorphous epilepsy.
Her parents, Rob Fehsenfeld and Janine Bolton, have endured sleepless nights caring for their little girl and are off to Mexico tomorrow for umbilical cord stem cell therapy, hoping to improve their little daughter's life.
The trip and the procedure will cost $40,000 and the Highlanders have decided to get involved.
They organised a movie night and quiz night and have signed two Highlanders jerseys to auction on the Trade Me website.
Cowan has also donated his signed All Black training jersey from last year's Grand Slam tour.
"It was the least we could do," Cowan said.
Bolton said the procedure was not funded by the Ministry of Health and it was both exciting and scary heading to Mexico.
The procedure will by performed in Tijuana by American medical staff.
Bolton said there were no guarantees for the procedure and success was different for every child.
The Brighton couple knew Highlanders wider training squad member Peter Merrilees, who put it to the team to get involved, and the team was totally supportive.
Bids for the jerseys can be made through the Trade Me website and then searching with the name darylann.
