It's safe to say that Serena Williams works hard to be the best — really, really hard.
"The other day I was on the court for four hours with my coach and everyone was like, 'OK, are you crazy?' No, I’m just really intense," she told FADER magazine in 2016.
All that "working hard" has included a pretty rigorous training schedule, especially as of late: The 23-time Grand Slam champ is currently competing in Wimbledon for the first time since winning the tournament in 2016, having taken last year off while pregnant with her daughter Alexis Olympia.
However, Serena's return to the court has come with a price: She just missed a major milestone in little Alexis' life.
"She took her first steps… I was training and missed it. I cried," the 36-year-old athlete tweeted early Saturday morning.
Little Alexis was born on September 1, 2017.
She's Serena's first child with her husband, Reddit founder Alexis Ohanian. She also just so happens to be one of the most adorable babies on the planet:
Those eyes, though!
Serena shares a lot of pictures of her daughter on her own Instagram account, but you can see even more on Alexis' personal account, @olympiaohanian. (Yes, this 8-month-old baby already has her very own Instagram account. Try to keep up!)
Serena's maternity leave came to an end in May, when she played in the French Open — her first time hitting the court since Alexis' birth.

She wound up pulling out of the competition with a pectoral injury just before her fourth-round match with Maria Sharapova. Fortunately, she recovered quickly and was able to start practicing for her next tourney — Wimbledon — about two weeks later.
Competition in Wimbledon began in late June, and so far Serena's been dominating.

It's her first time competing in the prestigious tournament since 2016. (She took last year off because she was pregnant with Alexis.)
She "cruised through" her first four matches, according to the "Guardian."

Clearly, the G.O.A.T. is back in her element.
But over the weekend, she got some devastating news.

Serena had missed seeing Alexis take her very first steps.
Her tweet about missing Alexis' first steps was met with an outpouring of love and support.

People from around the world replied to Serena's tweet to express their sympathy.

Serena is far from the first parent who's missed witnessing her kids' milestones, so it appears.

A lot of working parents were able to empathize with the tennis champ.

Some people — including model Chrissy Teigen — chimed in to remind Serena that milestones are only what you make of them.

Aaand now we're sobbing.
Not all is lost, though.
With Alexis in London to cheer on her mama, Serena is bound to witness a few of her daughter's major seconds and thirds.
And who knows? Maybe Serena will get to see Alexis swing her first (itsy-bitsy) racket!
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