A soldier who pleaded guilty to drug charges has avoided prison due to the effect it will have on her three-month-old baby.

Lance Corporal Kasey Rey Tapara, 31, has been dismissed from the New Zealand Army after pleading guilty to four drug charges.

Tapara admitted to taking MDMA at various North Island locations in 2018, including at popular music festivals Bay Dreams and Ohakuni Mardi Gras.

The supply technician, who has served in Iraq, also pleaded guilty to supplying and offering to supply the class B drug to fellow soldiers.

During the court-martial hearing, Major Woodman, the second-in-charge of Tapara's unit, said she lacked maturity and leadership skills, and had lost the trust of her battalion.

In an emotional oral submission, Tapara pleaded with the sentencing panels to consider a punishment that would allow her to stay with her baby.

"I'll do anything else, just don't separate me from my baby. She's my world," she said.

"I just want to apologise for my actions. My life has been turned upside down because I did something stupid, and it's been hard. If I could turn back the time I would."

The military reduced her sentence by 50 percent due to trial delays, remorse and an early guilty plea.

"However, it was her three-month-old baby that prevented her from imprisonment," Chief Judge Kevin Riordan said.

Military members dismissed her from service - ending a six-year career in the Defence Force.