What we learned about Barbara Bush from her famous granddaughters

And helping them keep things in perspective their whole lives, it seems, was their beloved grandmother, Barbara Bush. The 92-year-old former first lady of the United States died Tuesday at her home in Houston, a family spokesperson said.

Barbara Bush's central role in her granddaughters' lives was obvious in "Sisters First," the joint memoir the twins publishedlast fall and gave a sold-out talk about at the Book Festival of the MJCCA back in November.

The book covers all aspects of their lives -- including a hilarious account of their first-ever visit to Georgia during their "Gampy's" 1992 reelection campaign (former President George H.W. Bush ended up losing that race to Bill Clinton). Still, it's their "Ganny" (or "the Enforcer," as they also sometimes referred to their paternal grandmother) who kept popping up on page after page to command readers' respect, attention -- and smiles.

Over the years, Ganny laid down the law -- and took the twins to Italy when they turned 16 and bought them their first martinis at Harry's Bar in Venice.

Here are some other things that made the former first lady unforgettable in her granddaughters’ telling:

Her house, her rules: "On one visit, when my dad put his feet up on her coffee table," Bush Hager wrote, "she told him, 'I don't care if you are the president of the United States, take your feet off my coffee table.' And my dad did."

Her White House, her rules: Soon after their grandfather became president, the 7-year-old twins ordered up peanut butter-and-jelly sandwiches for delivery to them in the White House bowling alley. Bush Hager again: "We were like Eloise in our own Plaza!" Then the door opened and "Ganny" entered "and told us in no uncertain terms that we were not in a hotel."

Her fashion do and don't: Bush loved Keds sneakers so much, her husband gave her 24 pairs for her birthday one year when they were in the White House. But wait, it got better: "As she grew older, she became more accessible and playful as well," Pierce Bush wrote. "Sixty-year-old Barbara Bush might not have worn two different-colored sneakers, but by age eighty, she loved to pair a pink shoe with a red one from her closetful of colorful Keds."

The Enforcer was always on duty: Several summers ago, Bush Hager organized a family tennis tournament and made it to the finals. Egged on by her father, the former president, she celebrated her best shots by shimmying on court and even lifting her skirt at one point. A few weeks later, an envelope arrived at her New York apartment containing "a typed note addressed to both my dad and me. Like a lawyer building her case, Ganny recited my every unsportsmanlike infraction . . . Ganny was deeply disappointed with me because of my behavior, and angry that my dad had encouraged it."

Except for when she was needlepointing: Over the years, Bush needlepointed Christmas stockings for her entire, sprawling family. And in a section of the book that seems especially poignant now, Bush Hager, herself the mother of two young girls, wrote last year that her grandmother "is making a stocking reserve, so that all the great-grandchildren, including any who might be born after she passes away, will have a Ganny stocking to hang for Santa. She has even made a plan to have someone else personalize them if she is no longer able."

She held onto husband, in every sense: "My grandmother becomes softer and gentler around her husband of more than seven decades," Pierce Bush wrote last year. "In the last few years, she has willed him back from the brink of death several times. His obituary has been written, but Ganny wouldn't let him die . . . At ninety-two and ninety-three, they sleep holding hands."