Hlavac viewed the shows at the same time as the public and found it hard to watch her son kissing the girls.
She "didn't warm" to Alysha but liked Chrystal - "she was upfront and said her mind".
Hlavac said her son had found it hard and "confusing" to choose between Matilda and finalist Dani Robinson.
She told the Times the pair were giving the relationship the best chance to grow.
"He and Matilda are giving it their best shot and are just beginning on the journey. It will be hard, all the attention on them. Only time will tell."
She also said Green was eyeing up buying a house in the Bay.
"I can imagine myself living in Tauranga," Green told Hlavac last weekend, during a visit home.
She said the couple had been meeting up in Hlavac's brother's Titirangi house and recently spent a secret Bay weekend together, pottering around in Hlavac's Welcome Bay home, "hanging out" by the pool and tennis court. They even risked a trip to the local supermarket.
"I told him that was naughty, even though Matilda stayed in the car."
With the couple due to visit the Bay again in two weeks, could a move here be more permanent?
"He has been saving the deposit for a house ... and is nearly there. We have had conversations about him buying here ... possibly in the Mount or Papamoa and initially renting it out. It would definitely be more affordable here than Auckland."