Isla's name game!

After Isla Fisher, 35, and hubby Sacha Baron Cohen, 39, welcomed their second daughter last August, the pair kept her name top secret. The Rango star wouldn't even reveal the moniker when grilled on Live! with Regis and Kelly March 2.

Now sources exclusively reveal the six-month-old tot's identity to the new issue of Us Weekly (on stands now): Elula Lottie Miriam Cohen. Elula, the Hebrew name for August, joins big sister Olive, 3.

The reason for the secrecy? "Motherhood is my favorite topic but I never talk about it publicly," Fisher has said.

She adds: "As much as I love what I am doing, and I am so fortunate to have the opportunities that I have had, my responsibility is to my family."