She added that "what happened to Cleo is every parent's worst nightmare".
"Imagine putting your little daughter or son to bed, sleeping just metres away from them and waking up in the morning to find they had vanished," she wrote.
Allison wasn't the only star to react to the wonderful news of Cleo's rescue.
The Project host Carrie Bickmore also became visibly emotional when watching footage of WA police rescuing the little girl from a locked house in the early hours of Wednesday.
“That photo broke me today. It was a collective sigh of relief and a quiet sob this morning,” she said.
“She's such a sweetheart.”
Meanwhile, KIIS FM host Jackie 'O' Henderson also expressed relief over the revelation, saying on her show, "Oh, those parents must be so relieved! Oh, what they've been through is every parents' worst nightmare. It's so nice that she's been found alive."
In a statement following the astounding rescue, Deputy Commissioner Col Blanch said police "found little Cleo in one of the rooms" of the home in Carnarvon, Western Australia.
"One of the officers picked her up into his arms and asked her 'what's your name?'
"She said - 'My name is Cleo'.
"Cleo was reunited with her parents a short time later. This is the outcome we all hoped and prayed for."
A 36-year-old man was arrested near the home where Cleo was found, with police saying said he had no connections to Cleo's family.
