Bristol Palin may be only 20 years old, but the most famous daughter of Alaska's most famous politician is already releasing a memoir. Not Afraid of Life: My Journey So Far hit bookshelves Tuesday, and juicy details are already being teased. Palin's divulgence that she was drunk on "girly flavored wine coolers" when she lost her virginity to Levi Johnston already ignited the blogosphere over the weekend. Now, even more details are being shared. Here, five of the most talked-about revelations:

1. Bristol's son has a sibling

While she was dating Johnston, Palin writes that he "cheated on me about as frequently as he sharpened his hockey skates." She finally ended things with Johnston after discovering he had impregnated another girl, and named the child Bentley, "which was her first choice when they were naming Tripp," says TMZ. The shocker here, says Kirsten Boyd Johnson at Wonkette, is that Tripp has a half-brother.

2. Bristol and Meghan McCain don't like each other

The 26-year-old daughter of Sen. John McCain was cold to the family from Alaska, Palin writes. The first time the McCains and Palins met, Meghan "ignored us during the entire visit." She left such a bad impression that Palin instantly "had a sneaking suspicion I might need to watch my back." But Palin wasn't a very big fan of McCain's either, describing her as a "high-maintenance, back-stabbing brat," says Maureen O'Connor at Gawker. Indeed, Palin writes that she'd "never seen people with so much Louis Vuitton luggage, so many cell phones, and so many constant helpers to do hair and makeup" as John McCain's wife and daughter.

3. Cindy McCain offered to be Tripp's godmother

Palin writes that the 2008 GOP presidential nominee's wife "looked like a queen" and held herself "like royalty," according to ABC News. But Cindy McCain's offer to be Tripp's godmother rubbed Palin the wrong way. "I wondered why she wanted any type of guardianship over my child," Palin writes. Certainly, it was a "very strange thing to do," says Dan Amira at New York, "considering they had just recently met."

4. The cast hated Bristol on Dancing With the Stars

Palin has "not-so fond memories" of her stint on the reality TV show, says Sheila Marikar at ABC News, even though she and her partner Mark Ballas finished in third place. Her Dancing castmates "rolled their eyes when they realized we'd survived to dance another day," writes Palin. After some contestants were voted off, the cast's ire became even less subtle. They "literally would not speak to us or acknowledge our presence."

5. She wanted to take home a baby from Haiti

Thankfully, a good chunk of Palin's memoir is actually devoted to "chronicling her charitable work," says Alex Alvarez at Mediaite. After the 2010 earthquake in Haiti, Palin was visiting a cholera treatment center when she saw a father caring for an 8-month-old boy and six other children. "I could tell by his emotion and urgency that he was trying to give the baby up for a chance at life," she writes. Palin was so moved, in fact, that she offered to take the baby home. "But you obviously can't pick up a child and take him out of the country!" Still, she added, "It felt wrong to leave him there, though, whatever 'the system.'"