When Tori Spelling went into labor on March 13, she knew she was having a baby boy, but she didn't expect her estranged mom to be there with her and hubby Dean McDermott as they welcomed little Liam Aaron.

Yet, sure enough, Candy Spelling was in the delivery room at L.A.'s Cedars-Sinai Medical Center to greet her 6-pound, 6-ounce grandson.

"She had scrubs on!" a pal says.

So how did the mother and daughter (who had been feuding since Tori's father, Aaron, passed away last June) end their 9-month-long rift?

The peace process began with a series of e-mails and phone calls in the weeks leading up to Liam's birth.

"It was an extremely emotional, scary and exciting time for Tori, and she realized that she wanted her mother and brother there for it," says a pal of the actress, 33, who has a new OxyGen reality series with her husband called Tori & Dean: Inn Love.

"Candy was hesitant, but she knew Tori needed her."

Says a family source, "There were mutual apologies and discussions."

None of which surprises Tori friend Loni Anderson, who played her materialistic mom in So NoTORIous, Tori's 2006 VH1 series spoofing her life: "Tori couldn't wait to have a family of her own, and I know she hoped Candy would be a part of that."