Gisele Bundchen throws a giant snowball at husband Tom Brady, as son Benjamin and the family's dog Lua look on. Credit: James Haynes / Splash News

Supermodel's secret skill? Gisele Bundchen showed off her throwing arm in Boston on Jan. 3 when she started a snowball fight with husband Tom Brady and son Benjamin.

The Brazilian stunner, 33, was spotted lobbing a giant ball of snow at the NFL quarterback, 36, as her 4-year-old son Benjamin looked on in delight. The couple's daughter Vivian, 12 months, was nowhere to be seen, but the family dog, Lua, sat proudly in Benjamin's stroller. 

Weeks before their bundled up fun -- as much of the U.S. deals with both snow the impending "polar vortex" -- the photogenic brood wore next to nothing while soaking up the sun in Miami, with a bikini-clad Bundchen and her kids doing yoga surfside. 

The A-List family has been spending lots of quality time together, with Bundchen Instgramming a picture of the happy brood enjoying their Sunday on Jan. 5. 

"Perfect Sunday! #love #grateful #family," she captioned the picture of her lying on the ground while holding baby Vivian in the air above her. Next to her is her hubby of 4 years, also lying on the ground and playing with Benjamin. 

It looks like Boston snowstorms mean more family time for the Bundchen-Brady clan!