Camille Grammer wed fiancé David Meyer in Hawaii on Saturday

She may be the bride’s friend and costar, but Lisa Vanderpump opted out of attending Camille Grammer‘s Hawaiian wedding on Saturday.

“She’s going through a lot right now,” a source close to the reality star tells PEOPLE. “It’s not been the best time for her.”

The source says that the death of Vanderpump’s beloved brother Todd in May “took a toll,” and tensions with the other ladies on The Real Housewives of Beverly Hills have been at an all-time high.

“Lisa’s choosing not to film during any of the group activities,” says the source, who notes that the drama arose partly after Lisa Rinna allegedly called out Vanderpump for not joining in during a cast photo shoot.

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Now, “Lisa doesn’t want to be around the women as a group, so she’s getting less filming time. But nobody has quit. She’s definitely still on the show.”

For her part, Grammer, 50, says she “understands” why Vanderpump, 58, wasn’t present to see her wed lawyer David C. Meyer.

“I respect her decision,” Grammer tells PEOPLE. “Lisa was very apologetic about it.”

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Most importantly, Grammer says she’s eternally grateful for the support of her friend in helping her pursue lasting love with Meyer.

“She encouraged me to take a leap of faith on this journey,” says Grammer of getting married for the second time. “She really did. She told me, ‘You’ve got to take a leap!’”