Congrats are in order for Prince Harry and Meghan Markle! The new Duke and Duchess of Sussex said "I will" in front of roughly 600 people during their Windsor Castle wedding on May 19, but Meghan's estranged half-siblings weren't among those lucky guests. Thomas Markle Jr. and Samantha Grant (who goes by Samantha Markle on social media) are the children of Thomas Markle Sr., Meghan's father, from a previous marriage of his. Thomas Jr. is a window fitter from Oregon, Samantha is a Florida woman living with multiple sclerosis, and both sibs have aired a lot of thoughts about Meghan leading up to the ceremony. (Photo Credit: YouTube) As In Touch reported, Thomas Jr. wrote a letter to Prince Harry, warning him he was about to make "the biggest mistake in royal wedding history" and saying Meghan is a "jaded, shallow, conceited woman that will make a joke of you and the royal family heritage.