Sent out the $2.05 favourite under Blake Shinn, Estriella scored a 2-½ length win from Arkansaw Kid ($21) with Saltaire ($14) a half-length away third.
Maher said Estriella had an exciting career ahead of her, saying the filly still has an immature action and was learning all the time.
Estriella spends the majority of her time at Maher's Fingal property on the Mornington Peninsula but made the trek up to Cranbourne a couple of weeks ago for a 'tick over jump-out'.
The tactic worked as Estriella jumped straight to the front and led her rivals comfortably before increasing the tempo over the final 300m.
"She is a horse that has got so much in front of her," Maher said.
"She's got an immature action, and we tinker away with her and she's not there mentally either.
"It is about holding her together, harnessing her, as she's got so much in front of her.
"I thought last start, her last win was huge. She sat out there in no man's land and quickened up to win by herself.
"We thought that win would have taken a bit out of her."
Maher said there was options for the filly in Sydney and Adelaide in coming weeks.
The Group 2 Arrowfield Stakes (1200m) at Randwick on April 13 or the Group 1 Robert Sangster Stakes (1200m) at Morphettville on April 27 are races Maher said would come under consideration.
"With time, if we're kind to her, she'll be kind to us," Maher said.
Shinn said Estriella was a Group 1 winner in waiting.
"She's pretty special," Shinn said.
"She's got the frame of a four-year-old or five-year-old mare. It is just getting her mindset right, but she is learning all the time."
"I feel honoured to be riding a horse of this calibre at this point in time."
