Blue Ivy Carter Is 'Doing Great,' Says Beyoncé's Mom

By Carlos Greer and Dahvi Shira

02/09/2012 at 10:00 AM EST

Beyoncé and Jay-Z's newborn daughter Blue Ivy is already charming all the right people, including her grandma.

"She's doing great," a beaming Tina Knowles told PEOPLE at the Runway to Win fundraising reception for Barack Obama in New York. "She's beautiful."

As for her duties as a doting grandma, Knowles calls them "amazing," adding, "It's the second best job I've ever had."

Although her adoration for the new addition to her family was certainly instantaneous, Knowles is waiting to decide which parent little Blue resembles most.

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"She's only a month old," she says. "So we have to give her a minute."

Tina wasn't the only Knowles out and about this week. Beyoncé stepped out two nights in a row to support husband Jay-Z, who performed a pair of shows at Carnegie Hall.