Sai De Silva is breaking her silence after her marriage officially hit the skids ... and she says she's keeping the focus on her kids.

"The Real Housewives of New York City" star took to Instagram Saturday to address the split from her estranged husband, David Craig, just days after he pulled the trigger on their marriage.

Sai thanked fans for the "kindness, grace, and support," saying she's been flooded with messages and is feeling the love, but made it clear her priority right now is her two children.

Sai pointed out that living publicly comes with its challenges, adding people don't always know what's happening behind closed doors ... a not-so-subtle reminder there's more to the story than what fans see on TV.

We broke the story ... David filed for divorce Thursday after nearly a decade together. The two first met back in 2009 in Costa Rica. They later tied the knot in 2017 and share two kids, London and Rio.

Despite Sai's reality TV fame, David largely stayed out of the spotlight. He rarely appeared on her social media and only made occasional cameos on "RHONY," preferring to keep things low-key.

The split comes as "RHONY" is currently filming its upcoming season ... meaning this real-life drama will likely play out on screen.