"Actually she has a large family who were always there with her and for her," Grant tweeted following the prince's interview on BBC Radio 4's Today program. "Our household was very normal and when dad and Doria divorced, we all made it so it was like she had two houses. No one was estranged, she was just too busy. Read my book complete with facts and photos."
Grant, also known as Samantha Markle, is penning a tell-all book about her half-sibling.
"Meg's family (our family) is complete with sister, brother, aunts, uncles, cousins, and the glue of our family, our amazing completely self-sacrificing father," she wrote in another tweet. "She always had this family,..Marrying merely extends it."
She also added, "She has a large family. She always did. Our dad is amazing and completely self sacrificing. We made it so that she had two houses. How fun it was!"