Photos have also been released showing the 53-year-old writer and Phillips handing over the letter to palace security, as well as photos of her with her newly acquired party masks.
Deciding that she had nothing to wait, it is Saturday headed straight to Kensington Palace.
The confrontation came on a recent trip to the United Kingdom by Samantha Markle which she reportedly made in order to confront Meghan. Samantha, who suffers from multiple sclerosis, was pushed by her partner in a wheelchair through an open gate.
The source reportedly said: "She fully hoped they would let her in but she was turned away".
While she would not disclose the exact contents of the letter, she stated that it concerned their father, Thomas Markle Sr., who was forced to skip the royal wedding due to a health scare and was caught in a scandal with paparazzi.
The royals' family drama has played out in great detail in the public after a series of explosive incidents stemming from Meghan's decision to ban family members (bar her mother) from her royal wedding back in May.
"I just think that families can be this way when there's confusion and when people are hurt". She added, "Moving forward, I apologize and I wish things could be different".