Moran said servicewomen should not have to worry about paying their bills when they're getting ready to have a baby.
Zweygardt said Moran's bill would be life-changing for her and other expectant mothers in the National Guard.
"It would just be really important for me financially. We really depend on my drill income," she said. "This is going to give me the opportunity to really bond with my child."
The Military Officers Association of America released a statement backing Moran's bill, saying that "having a baby and juggling drilling responsibilities is cumbersome and not appreciative of the challenges of motherhood."
Lory Manning, a retired Navy captain and spokeswoman for the Service Women's Action Network, said that pregnant women have been serving in the military for decades, but prior to the 2016 policy change, each branch of the military handled maternity differently.
The military has sought to standardize how it treats maternity leave in recent years, but the National Guard has been left out of that change.
"The guard is always tricky because it's got two bosses. There's the federal component and then the governors," Manning said.
Manning also said that parental leave shouldn't be thought of as just an issue for female soldiers. It's an issue that affects fathers in uniform as well, she said.
Earlier this year, the Army broadened its parental leave policy to increase time off for secondary caregivers and to allow parents of either gender to be considered a child's primary caregiver.
Moran's bill deals exclusively with female members of the National Guard and reserves, but he said it opens the door to conversations about paternity leave as well.