The actress's character Vanessa Villante welcomed the arrival of Patrick in the soap's 2012 season finale, but a tough time lay ahead as the newborn became seriously ill with a heart condition.
Basquait Voevodin-Knack now has the role of Patrick in the show, and Sumarwata - who also has a young child in real life - couldn't be happier to be sharing scenes with him.
She said: "I definitely feel like his pseudo mum and it's been lovely watching him develop. There are lots of smiles now, however he is a cheeky thing - he saves it for the break and not when we're rolling!"
Basquait is the third youngster to appear as Patrick as the previous babies became too big for the role.
Neighbours' executive producer Richard Jasek explained: "As baby Patrick was quite ill when he was born in the story, we needed smaller babies in the role. Now he is well and growing, Basquait is just perfect. All the cast and crew adore him."
Neighbours airs weekdays at 1.45pm and 5.30pm on Channel 5 in the UK, and weekdays at 6.30pm on Eleven in Australia.
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