MELBOURNE, Australia - They've been asking her about it for a while, and now it's finally here - Maria Sharapova, a four-time Grand Slam champion and former World No.1, has finally signed up for Twitter.

Sharapova, who can be followed at https://twitter.com/MariaSharapova, sent her first tweet Monday.

Sharapova is no stranger to social media - she is the most "liked" female athlete on Facebook, with 9.2 million likes. And earlier Monday she was asked in her post-match presser about joining Twitter.

"Joining Twitter sometime this month?" she was asked.

"I am," she replied.

"When is that going to happen?" she was asked.

"It's a surprise," she said with a smile.

"Do you have a username picked out and everything?"

"Maybe," she smiled again.

"Can you give us a hint?"

"I would tell you if I could."