Britney Spears at LAX on June 18.
06/19/2008 AT 11:15 AM EDT
has arrived at the Mississippi hospital where her sister Jamie Lynn
is expected to give birth to her first child today.
On Wednesday, Britney – along with her father Jamie and brother Bryan – arrived in her hometown
of Kentwood, La., to be with Jamie Lynn. Mom Lynne has also been with Jamie Lynn, helping prepare for the baby's arrival.
The Spears family spent a relaxing evening together in Liberty, Miss., where Jamie Lynn recently bought a home, the night before. "They have had nine months to deal with this," says a Spears family friend. "Last night was very low-key. There was no last-minute panicking. No one was worried."