Tina Knowles dishes on Beyonce's daughter Blu Ivy's relationship with her twin siblings: 'She's a good sister'

Tina Knowles Lawson is one gushing grandma. Beyonce's mother recently opened up about her first-time experience with twins and her elder granddaughter's new role as big sister.

"They're doing great. They are absolutely beautiful and so much fun," the businesswoman told ET Online of four-month-old Rumi and Sir Carter. "I mean, I haven't ever been around twins, but it's so cute, I can hardly take it."

Tina said that it was already easy to perceive the differences between Beyonce and Jay-Z's two babies, who were born in June this year. "It's just really, really different with two babies. I mean, a boy and a girl," she said. "Very different personalities."

The 63-year-old has been playing a major part in helping her daughter out with the newcomers and said that the couple's five-year-old, Blue Ivy was also getting into her new role, describing her as a "good sister".

"Just seeing her grow up, it's bringing some maturity," Richard Lawson, Tina's husband added. "She's only five, but you can see the transition in terms of her being a little calmer.

"Because she's the diva," he added, "but she's sharing her diva-dom."

Most recently, Beyonce shared moments from her special mother-daughter time with Blue, when the two attended her creative director Todd Tourso's wedding back in August in New Orleans. They posed in the photo booth and even did a little dance for the camera.

Despite the arrival of the twins, it looks like Blue will not be running short of attention anytime soon. The five-year-old was clearly the belle of the ball at the wedding celebrations and joined her mother and other guests doing the signature dance move to Single Ladies.