Sharni says the new service will fill a huge gap in the Te Awamutu community.
"There are often pockets of women who are falling through the cracks of our health and social care systems," she says.
"These women don't have good family support, little or no parenting skills or knowledge, anxiety, birth trauma or postnatal depression," Sharni says.
Kaiāwhina will help with anything from folding washing and cooking to holding the baby while the mum has a shower or nap.
A Kaiāwhina does not take the place of a midwife, but works alongside them.
A Kaiāwhina's purpose is to support and uplift a mother, depending on her needs.
The confidential service will be available for mothers in the Te Awamutu, Kihikihi and Pirongia area referred by local midwives.
The Kaiāwhina volunteers will be handpicked for their passion for seeing mothers flourish.
They will be trained in first aid, mental health and for a range of situations including breast-feeding support, cultural safety and basic massage for a mother and baby.
The volunteers will initially be unpaid, but Sharni hopes they can be funded in the future.
Kaiāwhina falls under the umbrella of Loving Arms NZ, a community organisation Sharni founded five years ago that provides baby clothes, products and furniture to new mothers and babies in the Waipā district.
Sharni received a local hero medal in 2016 to acknowledge her efforts running the organisation.
Last year the service was the regional winner of the Trustpower Waipā Taupō Regional Community Awards.
Sharni is also a maternity consumer representative for the Waikato DHB's maternity quality and safety programme.
MP for Taranaki King Country Barbara Kuriger said she was in awe of Sharni.
"I have watched Sharni working tirelessly and passionately in her local community for the last five years.
Kaiāwhina is an incredible initiative that will change many lives and hopefully inspire others to take steps towards supporting new mums."
National Party deputy leader Paula Bennett said she was inspired meeting Sharni and hearing about the initiative.
"I believe the best thing we can do for children is to actually take care of the mothers, to empower mothers to take care of their babies best."