Fresh heir for Kate and Wills

THE ROYAL brood is growing.

Prince William and his wife, Catherine, the Duchess of Cambridge, are expecting their third child, Kensington Palace announced Monday.

“The queen and members of both families are delighted with the news,” the palace said in a statement. A spokesman for William’s father, Prince Charles, said he was “delighted at the news.”

The couple did not say when the baby was due.

The tiny royal will be fifth in the line of succession to the throne behind 2-year-old Princess Charlotte and 4-year-old Prince George, William and Kate’s first two children.

The children are behind their father, William, and their grandfather, Charles. The new baby will bump William’s brother, Prince Harry, down the line of succession.

Kensington Palace said that just like during her previous pregnancies, Kate is suffering from hyperemesis gravidarum — a disorder that can cause severe nausea.

As a result, she canceled an appearance at the Hornsey Road Children’s Center in London scheduled for Monday.