Some gals keep it low key when it comes to maternity clothes, but not Petra Ecclestone!

Petra showed off her growing baby bump in a snakeskin dress last night, and while the family was celebrating her 24th birthday at Giorgio Baldi, Tamara wasn't about to be outdone by her little sister! The busty brunette heiress also had some curves to show off, and um, wow. What else can we say? Girlfriend certainly knows how to render us speechless!

A preggers Petra Ecclestone and her sister Tamara went shopping at the Grove in Los Angeles yesterday, and naturally, the heiresses hit Barneys New York. But were they buying pricey duds for themselves or someone on their nice list? Perhaps a little bit of both?

Though Petra has yet to officially confirm the pregnancy herself, that growing baby bump says it all! This will be the first child for Petra and her hubby James Stunt, who tied the knot in 2011 after 4 years of dating. Congrats!

Petra Ecclestone is gearing up to be a first time mom.

The 23-year-old blonde stepped out with hubby James Stunt for a sexy date night at Madeo in West Hollywood.

The British Formula One heiress rocked a skintight grey mini dress and ankle boots. Talk about a tiny bump!

One thing's for sure ... that baby is going to be spoiled.

Mel Gibson grabbed a late night bite with Formula One heiresses Petra and Tamara Ecclestone at Boa in West Hollywood.

Petra recently dropped $85 milllion on Candy Spelling's Beverly Hills mansion. With that being said, wonder who picked up the bill?

Oh, to be a fly on that table.

Heiress Petra Ecclestone knows how to travel in style!

We caught up with Ecclestone as she headed to the gym and the doctor in LA -- and even in a casual hoody and leggings, Ecclestone works her wealth!

She was carrying a fabulously expensive Birkin bag and getting carted around in a custom Range Rover. Check out the back!

These besties just can't get enough of each other!

British heiress Petra Ecclestone, hubby James Stunt and heir Brandon Davis hit up Boa in West Hollywood again Saturday night. They were just there a week ago!

Boa was quite the melting pot of celebs that night -- also at the restaurant were Marilyn Manson, Girls Gone Wild mogul Joe Francis, Michael Lohan and Tara Reid and her new hubby.

If only they had all sat at the same table. Talk about dinner conversation! See photos of all the famous faces from the evening in our gallery below.

She's officially an LA girl now!

Billionheiress Petra Ecclestone looked ultra sexy in a pair of skin-tight purple pants and a black tank, as she cooled off with a sweet treat at Pinkberry in LA, on Thursday.

The gorgeous 22-year-old recently relocated to LA after marrying businessman James Stunt, and purchasing Candy Spelling's massive 57000 square-foot mansion for $85 million, last June.

The Formula One heiress was recently gifted a Rolls Royce by her new hubby, who had it hand delivered (with a bow on top!) to the Beverly Wilshire Hotel where the couple is currently staying during renovations to their new home.

Brandon Davis spent the better part of Friday with his new pal Petra Ecclestone, and whether it was going to Madeo or getting spray tans, they seemed to be joined at the hip! Mischa Barton's ex-boyfriend was later spotted chilling with Petra and her entourage at the Chateau Marmont, and after taking off from the Hollywood hot spot, the group headed to a private house party in the Hills. What a day!

So what's her sister Tamara been up to? She's been busy modeling the latest lingerie collection by Ultimo, and we have to say, she certainly looks like a million bucks! Click after the jump to see another hot shot of Tamara...