"I have a little bit of influence, being the older sister," says Venus. "But she still does what she wants to do - so if she doesn't come, don't blame me but I will tell her it is a great place to be."
For now the focus is on the elder Williams. She is a genuine legend of the sport, with numbers impressive from any angle. Seven grand slam titles and 44 tournament wins overall. More than $35 million in prize money and, for a period in the last decade, she was unbeatable, winning 35 consecutive matches and six successive tournaments.
"Venus [and Serena] created a new era in women's tennis," says 2011 ASB Classic semifinalist Julia Goerges. "They started serving very fast and hitting the ball very aggressively. Overall tennis is much, much better, fitness-wise [and] playing-wise."
But that was yesterday; next year will mark her 20th year on the WTA tour. Williams hasn't won a grand slam since 2008 (Wimbledon) and was last in a major final in 2009, also in London. She comes into tomorrow's tournament ranked 47 in the world after she was restricted to just 11 tournaments in 2013. The 33-year-old was diagnosed with Sjogren's syndrome (an auto immune disorder) in 2011, which saw her leave the tour for seven months.
"I've learned a lot," says Williams. "There is no manual on how to be a professional athlete with an auto immune disease. It is something that I have tried to make into a positive in my life. It's kept me going. I've been through this and never gave up so obviously I want to keep going."
Williams hasn't been in the top 10 since 2010 but is positive she has still got what it takes: "I'm always trying to improve my game; that is the point of being out here and being professional. If you don't [try to improve], you are going to get left behind. My motto is 'update, don't be late'.
"I have some goals but for me it is about playing well [and] every match leads to the next match. In my career, a lot of the losses have been important too because I learned a lot from those losses and they made me better. So, yeah, I want to win majors and I might have some losses but I will learn and it builds character."
Venus still has a big serve - and is a great mover - with a solid, reliable backhand and a crunching, powerful forehand. She is confident after the best off season she can remember and will be a dangerous floater in this week's tournament.
"I've had a nice break - it's been great," says Williams. "Now I need to get fired up and get the engine started again. Those two [top] seeds (Roberta Vinci, world No.14 and Ana Ivanovic, No.16) are playing well. I'm happy they are here; it gives me a chance to play them and maybe get my game on par."
She doesn't countenance talk of retirement - "I love tennis, I love the game and I'm still pretty good" - but when she eventually does, Williams is unlikely to get involved in coaching. A legion of former male grand slam winners (Ivan Lendl, Boris Becker and most recently Stefan Edberg) have taken on star pupils but Williams says a high-profile off-court role is unlikely.
"I'm not sure - you have to choose for yourself what you like to do in life," says Williams. "When you have been playing tennis since you were 4 years old, by the time you are in your 30s it's like, 'okay I've had enough travelling'. Maybe I would like to help young kids on the side somewhere in my home town when I am done playing - but I will think about that when it happens. I do other things off the court and I will probably pursue that."
Among her other pursuits, she (and Serena) is a proud part-owner of the Miami Dolphins, currently battling for an NFL finals position.
"It's awesome being an owner," says Williams. "This [Monday] if we win we are going to the play-offs - the [other] night I dreamed we won ... I love it, I love [being involved]."
In her debut appearance in Auckland, Williams assures that though this is a small tournament compared to the grand stages she has been on, she is focused and motivated.
"Everything is serious for me," says Williams. "I'm here and I'm a professional - it is all about being professional all week. When I am off the court I am off the court; when I am on the court I am 100,000 per cent. No matter what the tournament is I'm here to get a win."
