"Breastfeeding is an incredibly personal thing", said Williams, an advocate for breastfeeding.
Australian doubles player Arina Rodionova also questioned its legality. "Every day is a great day I'm excited to. fight my heart out".
In the end, Williams had to have a filter inserted into a major vein to prevent any possible clots from entering her lungs, and was forced to go on bed rest for the next six weeks. "I was terrified, and it was a whole new kind of fear".
After the win Williams said: "All the moms out there that had a tough pregnancy and have to come back and try to be fierce, in the middle of everything".
The 36-year-old, seeking a 24th Grand Slam title, will face Germany's Julia Goerges for a place in the last 16.More news: 'Roseanne' Cancelled After Barr's Racist Tweet
"The biggest difference is definitely I'm semi on time today", she continued. Any surgery that Serena has is potentially life-threatening.
She said, "The truth is I miss my body, being able to do other kinds of fantastic things".
"It's not a typical outfit". So you know, she's got a chance. Who makes the rules?
"I feel like a super hero when I wear it". She said this sparked a "slew" of health complications. Everything is allowed. Because once she gets her engine going, the lack of fitness. the long 15-month absence. the world ranking (451 at the start of the tournament). the improbability of it all. everything, goes out of the window.
"Oh God, I'll never be a size four", she declares.
Williams had all sorts of trouble in the opening set, compiling 12 unforced errors. But Williams' movement around the court is not as slick as she would like - although she has played only five singles matches since her daughter's birth.
Pliskova had an early break in the second game of the second set to take a 2-0 lead but Williams broke straight back.