Despite the exhausting labour, Mrs Wallace says she feels in better health this time around.
"It's good, because we're able to get up and away quicker this time," she said.
"With a C-section, you're recovering in hospital for ages. It's quite major surgery.
"I am feeling a little more relaxed this time too. You know a bit more of what to do the second time."
Big sister Charlotte met her new sibling shortly after her birth.
"Charlotte liked her," said Mrs Wallace.
"She had a little posy of flowers for Matilda. She went right up to her and gave her a big kiss and cuddle.
"It was really cute."
The couple, both farmers, hope to take Matilda home to Wainuioru today.
"You always look forward to going home from hospital," said Mrs Wallace.
"But it is nice to press a button in the middle of the night and have someone bring you a cup of tea."
Mr Wallace said he was "proud as punch" of his new daughter.
"We didn't know if we were having a boy or girl but she was a good surprise."
The Wallaces expressed thanks to midwife Kate Wilson, who assisted at the birth.