Blake and Robyn's mother, Elaine Lively, was also at the event on Tuesday night.
It was a ladies' night out for the Lively women!
On Tuesday evening, Blake Lively joined sister Robyn and mother Elaine on the red carpet of Lorraine Schwartz Eye Bangles Collection launch at Delilah in West Hollywood, California -- and needless to say, they slayed!
Blake wore a figure-hugging spaghetti strap black Brandon Maxwell dress that she paired with embellished sandal heels, large hoop earrings and several statement bracelets on her left wrist.
As for Robyn, 46, she went for a simple strapless, floor-length white dress that she too accessorized with big hoop earrings.
The stunning sisters also posed with their mother and Robyn's husband, Bart Johnson, and an eyewitness told ET that Blake was adorably assisting her family with their positioning on the red carpet.
While at the event, Robyn chatted with ET's Lauren Zima about the family's connection to jeweler Lorraine Schwartz and offered an update on Blake following her on-set injury.
In December, the 30-year-old actress hurt her hand while filming The Rhythm Section, and a month later it was reported that production on the British-American spy thriller had been suspended indefinitely. On Tuesday night, Blake was sporting a black bandage on her right hand.
"She's alright," Robyn said of her sibling. "She's doing amazing."
In addition to acting, Blake has designed some jewelry with Schwartz. In fact, an eyewitness at the event told ET that Schwartz was heard saying that Blake co-designed the hoop earrings she was wearing.
"My sister's incredible like that," Robyn gushed. "She's multi-talented."
The Teen Witch star also had a lot of love for Schwartz as well, and was thrilled to be celebrating the jeweler's Eye Bangle addition to her Evil Eye collection. "[We're here to] support Lorainne and her beautiful bangles. We love Lorainne!" she exclaimed. "She's family to us. We wouldn't miss it for the world."