In the past Jools has spoken of difficulties in fulfilling her dream of a big family after being diagnosed with polycystic ovaries. The 34-year-old underwent IVF to have the girls, though a spokesperson for the pair has confirmed the latest addition was conceived naturally.
And school dinners crusader Jamie is said to be hoping the impending arrival injects some testosterone into his all-female household.
"He would love a boy as it's only girls in the house now," a friend of the couple revealed. "Poppy and Daisy are so excited and already thinking about being big sisters."