A "Save Midwives" meeting last Friday was expected to draw a crowd of about 90, Kellett said.
"A lot of women wanted to show support for us, so it was really about educating anyone who didn't completely understand how the system worked."
Kellett said it was about educating MPs about midwives and explaining to people exactly why midwives were now asking for something to change.
"Because we've done so much and tried so hard and haven't been heard."
Tauranga-based Labour list MPs Jan Tinetti and Angie Warren-Clark both cancelled before the meeting and so did Tauranga-based NZ First list MP Clayton Mitchell. All three were initially confirmed to be there.
"It seems so strange to be committed to a meeting, to realise that many people were coming that wanted to support the event, and then not come," Kellett said.
Tinetti said she found out on Monday she was required elsewhere on Friday and was upset she had to cancel.
"I'm hoping my office can organise a time that at the very least the key personnel can meet me."
Warren-Clark said she was "whipped" at short notice to cover a compulsory select committee meeting in Thames.
Mitchell said he had an urgent matter to attend with a constituent.
He said it was a shame all of the MPs were unable to go to the meeting and gave his "humble apologies".
Tauranga MP and National Party leader Simon Bridges and National Bay of Plenty MP Todd Muller were both invited at the last minute, Kellett said.
"So it was understandable that they couldn't make it."
Muller instead scheduled a closed-door meeting with Kellett and a few other midwives next month.
The Bay of Plenty Times did not receive a response from Bridges before publication.
The cancelled meeting has been replaced by a public march in Tauranga on May 3 to coincide with the midwives' march on Parliament, when they will deliver hundreds of letters to Health Minister David Clark.
The New Zealand College of Midwives began fighting for pay equity across the country three years ago.