"I've seen him change in the last couple of months. It's big," said Sara.
"He's really been confident and I'm so proud of him, even if he loses I'm proud. But I'm happy with what he's been doing, he's been working really hard the last nine weeks, and if he believes, he can do anything."
Tomic engaged in a spot of friendly banter with Federer before coming up against him in the third round.
However, the Swiss legend told the Australian that he has to keep working hard if he wants to break the world's top 10.
Sara believes that this is valuable advice coming from such a decorated professional.
"I saw Federer talking and he knows how hard it is to be top-10 because he's one of the world's best players, and it's just interesting how you see someone who's up there saying how tough it is when Bernard's just a little bit under," she said.
"He just needs to know how really hard it is."
Tomic won his first title at the ATP Sydney International before competing in Melbourne.