Prince William thinks Princess Diana would have been a "nightmare grandmother".
The 35-year-old royal would have loved for his late mother - who died in August 1997 - to have met her grandchildren Prince George, four, and Princess Charlotte, two, but quipped she would no doubt "cause an amazing scene".
He said: "She'd be a nightmare grandmother, absolute nightmare. She'd love the children to bits, but she'd be an absolute nightmare. She'd come and go and she'd come in probably at bath time, cause an amazing ... scene, bubbles everywhere, bathwater all over the place, and then leave."
William's own parenting style is inspired by his late mother's.
He added: "I want to make as much time and effort with Charlotte and George as I can because I realize these early years, particularly, are crucial for children, having seen what she did for us."
And William likes to talk to George and Charlotte - who he has with Duchess Catherine - about their grandmother so they know she existed.
Speaking on the Diana, Our Mother: Her Life and Legacy documentary, he shared: "We've got more photos up around the house now of her and we talk about her a bit and stuff. It's hard because obviously Catherine didn't know her, so she cannot really provide that ... level of detail.
"So, I do regularly, [when] putting George or Charlotte to bed, talk about her and just try to remind them that there are two grandmothers - there were two grandmothers - in their lives. It's important that they know who she was and that she existed."