Tomorrow's showdown is particularly poignant for her son. He is the only cricket player to have represented both Australia and New Zealand and the first since South African Kepler Wessels, just over 20 years ago, to represent two major nations.
Born in Dannevirke, Ronchi, now 33, moved to Western Australia with his family aged 6. He debuted for the Australian team in 2008 but was eventually forced out of contention by wicket keeper Brad Haddin.
Ronchi, passionate about the game, moved back to New Zealand in 2012 in a bid to compete again at the top level. He was picked for the Black Caps in 2013 and is considered one of the world's top keepers.
Asked what it meant for her son to be facing off against his old team in tomorrow's Cricket World Cup final, Mrs Ronchi said: "That's something you'd have to ask him. But I tell you what - he's definitely a Kiwi. He loves what he's doing at the moment. He loves the Kiwi team and the culture within it. He is having the time of his life."
He got his first cricket set from his grandparents at 2 and used to "harass" family members to lob him balls in the backyard.
As a teenager playing for the Perth Cricket Club, Ronchi received prized hand-me-down gear from his mentor Adam "Gilly" Gilchrist, who went on to keep wickets for Australia. A natural athlete, he also excelled in rugby, Aussie rules, basketball, indoor cricket and volleyball.
Perth Cricket Club president John Lindsay recalls Ronchi being a talented yet unassuming youngster who loved the game. "It was pretty obvious he was going to be something special."
Mr Lindsay is torn. "I want him to make 100 but I want Australia to win by a run."
Luke Ronchi, 33
• Born in Dannevirke but moved to Western Australia aged 6
• Wicket keeper/right-hand batsman
• Nickname: Rock
• Only player to have represented both Australia and New Zealand at international cricket