Hoping to end their ongoing feud, Tori Spelling invited her estranged mother Candy to daughter Stella's first birthday party this past Saturday in Encino, Calif., sources tell Usmagazine.com.

Candy's camp RSVPed yes, but she never showed up (despite complaining in many interviews that she has never met her granddaughter).

Sources add that Candy's camp even called in advance and asked if camera crews for Tori's Oxygen show would be present. Tori assured them she would be respectful of her mother's wishes if she didn't want to be filmed.

"She still chose not to come," says a source.

Take a peek at Tori and husband Dean McDermott's family photo album

A Candy source tells Us, "Candy did RSVP to the event but decided not to attend when she found out there would be cameras there. She wanted it to be an entirely private meeting."

But a Tori source says Candy "knew there would be cameras and had her people call a week before to have the photo releases sent over."

See then-and-now photos of your favorite 90210 stars

"She waited until one hour before the event to notify Tori, by email, that she wasn't attending," adds the source. "Tori was busy preparing and didn't get the email until after the party. She was waiting for her mom the whole time."

As for Candy's concerns for privacy, the Tori insider tells Us, "It was a big party and there was plenty of opportunity for a private meeting."

See Tori Spelling and other moms in bikinis

Tori and Candy have been estranged for some time.

Their feud took a new twist late last month when Candy remarked that Tori had abandoned her father before his 2006 death and "that's what killed my husband."

Tori has never revealed the reason she doesn't talk to her mother. (She has vaguely said they just "don't go together.")

See Tori Spelling and other stars at fashion week!

In April, Candy -- who released her frank memoir Stories From Candyland a few weeks before Tori debuted her book, Mommyhood -- posted a public letter to Tori on her website, pushing for a reconciliation.

But Tori told Usmagazine.com in April, "If I said one thing to my mother, it wouldn't be public because if she does intend to have a relationship with her grandchildren -- which I am totally open to -- I just would like her to approach us privately."