Three-year-old filly Intravenous is already one step ahead of her Group One-winning sibling Platelet.

Platelet ran second on debut at Echuca but Intravenous was a smart first-up winner at Donald, leaving her one-up on her half-sister.

However, the Darren Weir stable insists that is where the similarities end.

"Intravenous is not as good as Platelet," Weir's racing manager Jeremy Rogers said.

"They are a bit different because Intravenous will get over a bit more ground than what Platelet does."

Intravenous will jump into a benchmark 70 contest when she runs in Wednesday's Slickpix Handicap (1000m) at Sandown.

The filly defeated her Australasian Oaks-bound stablemate May's Dream in a barrier trial before her Donald victory.

However, Rogers said Intravenous had things go her way in her maiden win.

"She had a lot of favours that day at Donald but she did win the race in style," he said.

"It's a massive rise in class at Sandown but she couldn't have been more impressive on debut."

Intravenous has been sent straight to city class in a bid to boost her broodmare value.

Platelet is progressing well ahead of her bid to record back-to-back wins in both the Group One Sportingbet Classic and the Group One Goodwood in Adelaide.

She scored a brilliant first-up win at Moonee Valley on March 21 and Rogers expects the five-year-old has improved from that outing but will benefit from another lead-up run in the RN Irwin Stakes at Morphettville on April 12.

"We are taking exactly the same path with her going into the Sportingbet Classic and the Goodwood," Rogers said.