“I think the surprise of knowing what you are going to have on that very special day you give birth is probably the best surprise you can ever have,” the pregnant tennis champ wrote on Instagram Thursday morning.
Fans of the 35-year-old mom-to-be were freaking out recently when big sister Venus Williams referred to Serena’s upcoming baby as “she” — with many speculating that the four-time Olympic gold medalist had accidentally revealed the gender of her future niece (or nephew).
When asked what Serena’s child will call her, 36-year-old Venus told Eurosport on Wednesday, “She’s going to call me ‘favorite aunt.’ ”
Want all the latest pregnancy and birth announcements, plus celebrity mom blogs? Click here to get those and more in the PEOPLE Babies newsletter.
RELATED VIDEO: Ace Maternity Style! Pregnant Serena Williams Shows Off Baby Bump At Met Gala
Venus also shared that she and her other sisters, Lyndrea Price and Isha Price, are hoping that the tiny tot will bear one of their names.
“We’re all like, ‘Baby V, Baby Lyn, Baby Isha,’ ” Venus said. “We all want the baby to be named after us.”
But on Instagram Thursday, Serena explained that “she” is just a catch-all term they’ve adopted.
“To clarify what Venus said, I am always joking with my sisters to see what favors I can get them [to] do for me next. If I want something from one of my sisters, I say ‘Baby Venus, Baby Lyn, or Baby Isha needs it.’ I did not grow up with any brothers, only sisters and we all say ‘she’ more than ‘he.’ ”
“Unless I’m joking with my dad or Alexis and I’m trying to con something out of them too,” she added. “Hey, I’m the youngest [of] 5 — I’ve always tricked all of them, what can I say!”
“We’re waiting for a surprise,” she said. “We call it ‘Baby.’ ”
FROM PEN: How Today‘s Savannah Guthrie Copes With a Toddler, a Newborn AND 3 a.m. Wake-Up Calls!
The duo said they’re also trying to figure out living arrangements, weighing if they should raise their family in Ohanian’s current home base of San Francisco.
“That’s the question of the hour,” Williams said, adding, “I couldn’t be stuck in a more beautiful place.”