They will be making the cut at Tonz Barber Shop in Queen St on Friday, and Ashleigh said they will be getting the closest shave possible.
"Kids with cancer don't get to keep any little bit of hair, so why should we?"
Ashleigh signed up for Shave for a Cure after Aisleen told Facebook friends she was on board.
"I have had family and friends lost to cancer, and I know where they'd be sitting right now, they'd be happy," said Ashleigh.
She said she is nervous about the shave, but is unlikely to run screaming from the barbershop.
And Aisleen said she has no choice in the matter.
"I used to be a prop, so she's not going to get past me."
For Aisleen, it's nothing - she has already had her hair shaved once, has worn a mohawk, and is currently sporting a pink and purple fringe.
"I think it's a good cause," said Aisleen, "Why not try and help?"
Six New Zealanders are diagnosed with a blood cancer or related condition every day, and money raised goes towards support patients and their families.
If you would like to support Aisleen and Ashleigh to raise money go to www.shaveforacure.co.nz, go to Shavees, and search "Shave and Be Brave" where you will find their profiles.