"We are at breaking point. We cannot work the hours we are working and provide the care we are expected to give and still be alive ourselves."
The 53-year-old said she stepped into midwifery in a bit of a "mid-life crisis".
"I come from the UK and always wanted to be a midwife but the model of care over there isn't great. New Zealand is known to have a great model of care - so that part is good."
But what she didn't know was the struggles midwives faced.
"The continuity of care in New Zealand is great - in the UK you have to go private if you want an assigned midwife - but they are starting to adopt New Zealand's care model.
"But the continuity of care isn't reflected in our pay and we do some much work for free."
LMC midwives work in the community and take on pregnant women as they see fit.
The Government pays them the same amount per woman - about $2300 - and pay does not increase with experience or complex pregnancies.
One message Williams said she wanted to make clear was how passionate midwives in New Zealand were.
"We don't want any mother to think we resent what we do. It's the best job in the world."
She said the problem was that for the past two-and-a-half years the New Zealand College of Midwives had been working carefully with the National Government to come up with a well researched design that was ready to be signed off.
"But with the change in Government all that's up in the air and everything is at risk."
She said after the $58,000 student loan she gathered from her midwifery studies she may be forced to give it all up.
"If nothing changes after this march, I'll be forced to walk - along with many others."
