These viewing arrangements were a subtle nod to the royal family's pecking order - which Kate is reportedly keen to enforce, especially in light of the Queen's most recent show of favouritism toward new royal Meghan.
The event came just days after palace sources revealed that Elizabeth had broken an unwritten royal rule by inviting pregnant Meghan's mother, Doria Ragland, to join the family for Christmas at her Sandringham estate.
"Kate is livid - not once has her family spent the holidays at Sandringham!" a royal source spilled to In Touch, noting that the Duchess of Cambridge was already annoyed when Meghan was allowed to attend last year, before she was even getting married.
Kate was never given the chance during her nearly eight years of dating William before they wed).
According to In Touch, Kate feels the Queen is giving Meghan special treatment.
"On Christmas Day, Kate and William make a huge effort to split their time between the Middleton's and the royal household - it's hardly what you'd call a relaxing day. Things would be much easier if everyone was under one roof," says the source, adding that Kate sees it as a "huge snub" to her parents.
The US tabloid notes Kate's sympathy toward Doria, who has no other children to celebrate the holidays with, adding "but she still thinks Meghan's got it easy compared to what she had to go through."
In Touch's report adds "tensions between the duchesses has already taken its toll."
"Since Meghan has come into the picture, the dynamics have changed," a source told the US tabloid.
"William and Harry aren't as close as they once were."
The Royal Family are yet to respond to In Touch's report.