For many parents deciding how many children to have isn't an easy one. Mama of three Kate Hudson welcomed her baby girl Rani Rose in 2018 and has two older sons, 16-year-old Ryder Russell and 8-year-old Bingham Hawn. Her family is beautiful, but it may not be complete. "I don't know if I'm done yet," Hudson said during a recent appearance on The Ellen DeGeneres Show. Hudson shared her reason for considering baby number four....and it's pretty relatable to fellow toddler mamas. "Right now, Rani's in that place where you're like, 'I want another baby,'" Hudson explained. "But once she gets like four, five, you're like, 'I feel like my life is kinda back a little bit. They're kind of in a groove.' There's, like, a window." There totally is a window, and it's 18 to 59 months, according to data from the CDC. More than half of the siblings born in recent years have an age gap between 18 months (1.5 years) and 59 months (4.91 years). In this way, Hudson is pretty out of the ordinary as she's had longer interpregnancy intervals than most American moms with her first three kids. The gap between her sons is 89 months and the gap between her middle child and her youngest is 87 months. According to the data, women in Hudson's current age group (30-44) are more likely to have longer interpregnancy intervals than younger moms, but only 20% of interpregnancy intervals are over 60 months. Hudson's revelation about her family size came as she spoke to Ellen alongside her brother, Oliver Hudson to promote their new podcast, Sibling Revelry. The brother/sister duo also chatted about parenthood. Both have three children...but something may happen to break the tie.