Pregnant Kate Middleton’s Siblings, James and Pippa, Visit Her in the Hospital

Pippa And James Middleton seen leaving The King Edward VII hopsital on Dec 5, 2012. Steve Finn/Splash News Online

Supportive siblings, indeed!

Two days after Kate Middleton was admitted to London's King Edward VII Hospital for acute morning sickness, the 30-year-old Duchess' siblings, James and Pippa Middleton, visited her for the first time Dec. 5.

"They arrived at the hospital at 3:50 p.m. in a black taxi," a source tells Us Weekly. "They left at 5 p.m." Prince William, who had been by his wife's side all morning, left at 5:10 p.m. local time.

On Dec. 4, a rep for the royal couple told Us Weekly Kate "is continuing to feel better" after being hospitalized the day prior for hyperemesis gravidarum, a rare condition that can cause severe nausea, vomiting, weight loss, dehydration, lightheadedness and fainting.

As Kate receives medical attention, the Church of England has published a prayer for the expectant parents: "We pray for William, Duke of Cambridge and Catherine, Duchess of Cambridge, as they prepare to receive the gift of their child."

The Earl and Countess of Wessex, Prince Edward and Sophie Helen Rhys-Jones, wished the mom-to-be well at a London engagement that same day. "We have deep sympathy with Catherine," Edward said. "We know someone who had the same condition."

Added Rhys-Jones, "It really is a perfect end to pretty great year."

Both William and Kate have spoken candidly about their desire to become parents since tying the knot in April 2011. "Trying for a baby has been their priority," a royal confidant told Us prior to their Dec. 3 announcement that Middleton is expecting. "They're both excited to be focusing on a new chapter in their lives."

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