Serena-Venus sister act has family feud elements

When Serena and Venus Williams meet Tuesday for a US Open semi-final berth, there will be plenty of sisterly respect but more than a bit of sibling rivalry involved too.

World number one Serena, chasing the first calendar Grand Slam since Steffi Graf in 1988 with her seventh US Open title, could also capture her 22nd Grand Slam title to match Graf's Open Era record.

"There's always another record, always another person to catch up with or pass," Serena said.

"I never really thought I would be in this position where I would even be talking about records, talking about passing Steffi Graf or even mentioning Margaret Court. I just grew up trying to be the best that I could. So to even be mentioned in that conversation is great."

But Venus, 35, could be the spoiler to the calendar Slam, the seven-time Grand Slam champion having played well to book her last-eight date against a little sister who has been a friend and rival since they were children.

Serena, 33, owns all four major titles for now. She leads the Williams rivalry 15-11 in all matches and 8-5 in Grand Slam events.

Serena said her biggest annoyance with her older sister, apart from all the matches she won when they were children, was how her own dog runs to Venus when she is around.

For Venus, it's how the annual family gathering is sorted.

"We have a family gathering every year and every year I don't get much say," Venus said. "She always picks the theme, and so that bothers me."

"Her team are just haters, to be honest," Serena replied.

"They're jealous. We'll just let it slide off our shoulders. We don't take it personal."

That's how she has treated the pressure of chasing history as well.

"I've been really rather relaxed," Serena said. "I don't really feel like if I win this tournament it's going to make or break my career."

Serena won't be letting up on Venus, but she might not be as demonstrative with her fist pumps and screams.

"I just try to be more internally excited," Serena said. "I still have a few 'Come ons,' maybe not as many, but I'm definitely as intense."

Venus knows to expect a powerful game from Serena, as opposed to other rivals who raise their games when across the net from her.

"I play a lot of opponents who just play out of their head, that's kind of a usual day for me. There's no easy days," Venus said.

"At least you expect that from Serena. She's not playing at a level that's abnormal. It's just her level."

While Serena could break her own record as the oldest Grand Slam champion set when she won Wimbledon in July, Venus is looking at life after tennis once the duo team up to defend Olympic gold next year.

"There's a big part of me that wants to be able, not to move away from tennis, but to explore other things in life and to transition and to find new challenges," Venus said.

"Of course I will always be involved with tennis, but it's a certain challenge when you try something new. I love that."