Twins Day One August 7, 2002 at 12:28 AM EST - Updated July 10 at 7:51 PM Conjoined twin Maria Teresa is back in intensive care with her sister after nearly five hours of surgery to clear up bleeding in her brain. Both of the one-year-old girls are in critical but stable condition after a marathon operation to separate them. They were born joined at the top of the head, facing in opposite directions. They shared bone and blood vessels, but have separate brains. The family at home in Guatemala is keeping a close eye on their progress. Juliana (hoo-lee-AH'-nuh) Hernandez, the twins' 85-year-old great-grandmother, says she'd love to give them a hug. All 500 people in her village went to Mass last night to pray for the little girls, "asking God to guide the doctors' hands during the surgery," as their grandmother says.