Scouting? Not really. More like rooting. And when Thursday's second semifinal ended, Williams stood, smiling and applauding for the woman who won, the woman she will have to beat to earn a fifth championship at the All England Club: her younger sister, Serena.
The most unusual and, at times, uncomfortable rivalry in tennis is once more in the spotlight at the pinnacle of the sport: Venus will play Serena in their third all-in-the-family Wimbledon final Saturday.
It's their seventh Grand Slam title match - Serena holds a 5-1 edge over her sister - but first final at any tournament since 2003.
"Our main focus is obviously both of us getting to the final," Venus said. "Then, from there, it's every Williams for themself."
While there are, of course, differences in personality (Venus calls herself a nerd; Serena is more extroverted) and game (Venus' serve is faster, for example, and Serena's return is considered better), the siblings' paths to what will be their 16th head-to-head matchup were remarkably similar.
Neither has lost a set in the tournament, and Venus won her semifinal 6-1, 7-6 (3) over fifth-seeded Elena Dementieva of Russia 6-1, 7-6 (3), before Serena hit 14 aces in a 6-2, 7-6 (5) victory over 133rd-ranked Zheng Jie of China 6-2, 7-6 (5). Coincidentally, each Williams won 80 of the 141 points in her match.
How unsurprising were Thursday's results? Consider this: The sisters are now a combined 100-13 at Wimbledon for their careers; Dementieva and Zheng are a combined 29-13.
"We've both been working extremely hard," said Serena, who holds an 8-7 career edge over Venus. "It's just coming together."
Both have been ranked No. 1, but a combination of injuries and inactivity contributed to Venus being No. 7 now, and Serena No. 6. All of the top four-seeded women were gone by the quarterfinals, the first time that's ever happened at Wimbledon, which cleared the way a bit for the sisters.
Then again, they way they've been playing over these two weeks, and the way they always seem to play on grass, who's to say it would have made a difference?
Back on May 30, when the city was Paris and the surface clay, first Serena, then Venus, lost in the third round at the French Open.
A little more than a month later, defending champion Venus, 28, will be going for her fifth title at Wimbledon, and seventh major overall; Serena, 26, will be going for her third title at Wimbledon, and ninth major overall.
They've combined for 11 finals appearances since 2000 at the grass-court Grand Slam tournament, including when Serena beat Venus for the 2002 and 2003 titles.
"They're both going to show up, and they both want it," said David Witt, Venus' hitting partner, who also has worked with Serena. "So it's special."
One interested party who won't be there Saturday: Richard Williams, the architect of the greatest one-family dynasty in tennis history.
The father and coach who decided to teach his daughters how to swing rackets in Compton, Calif., and has seen them grace the game's greatest stages, hates seeing them slug it out against each other. So he's flying home to the United States. Won't even follow the match on TV.
"I can't stand to watch them play," he said between puffs of a victory cigarillo once the semifinals were over. "I can never do that. It makes me nervous."
It's not hard to fathom how tough it must be to try to beat your sibling, and the all-Williams matchups haven't always brought out their best play - although Serena pointedly objected to that assessment Thursday.
After Dementieva ended her loss to Venus with five consecutive groundstroke errors, she was asked about the final and said she couldn't imagine facing a sibling, adding, "For sure it's going to be a family decision."
That was interpreted by some as a comment similar to what Dementieva said in 2001 following a loss to Venus in the quarterfinals of a tournament at Indian Wells, Calif., setting up a Williams-Williams semifinal. Asked to predict the outcome, Dementieva said then: "I don't know what Richard thinks about it. I think he will decide who's going to win."
Dementieva's comment Thursday was relayed by a reporter to Venus, who said: "Any mention of that is extremely disrespectful for who I am, what I stand for, and my family."
Later, Dementieva issued a statement through the WTA saying English is not her first language and clarifying her comments: "What I meant was it is a unique situation for a family to be in, to be playing for a Grand Slam title."
That it is. The only other sisters to play each other in a major final were Maud and Lillian Watson, who met to decide the very first Wimbledon championship - all the way back in 1884.
"I personally want everything that Venus has," Serena said. "We're good at this now. We just leave everything on the court. This is the finals of Wimbledon. Who doesn't want it?"
While No. 1 Roger Federer plays Marat Safin in one men's semifinal Friday, and No. 2 Rafael Nadal meets Rainer Schuettler - who needed two days to finish his five-set quarterfinal victory over Arnaud Clement - in the other, the schedule also includes the women's doubles semifinals.
The Williams sisters will play Nathalie Dechy and Casey Dellacqua in that event, then return to the apartment they're sharing during the tournament.
Unlike any other two opponents the day before squaring off in a major final, they'll share a table for dinner. While Venus might later unwind by reading a book and Serena probably instead will opt to watch a TV show, it's not as though they'll avoid speaking to each other, even if the topic most likely won't be tennis.
"I mean, we're living together. It would have been kind of weird if we didn't talk to each other," Serena said, then added with a mischievous twinkle in her eye: "Maybe I should try that. It will be like really intimidating or something."
Sometime Saturday afternoon, weather permitting, one Williams sister or the other will be able to declare that she is, at least for the moment, the best player in the world - and in her family.