The US publication alleges to have learnt the Queen plans to leave money to her favourite new protege, Meghan, even though she the 37-year-old former actress has been wed to the Queen's grandson, Prince Harry, for only a few months.
That news has sent shock waves through the House of Windsor.
'The way some of them see it,' says a palace insider, 'Meghan will be inheriting money that should be theirs.'
Prince Charles, the Duchess of Sussex's new father-in-law, is one of the most outspoken protestors, In Touch claims.
'He believes that the Queen should get to know Meghan more before making any rash decisions,' says a palace insider. 'He's accused his mother of thinking with her heart, not her head.'
Plus, Charles has to worry about his mother leaving Meghan a chunk of money but not including his wife, Camilla, Duchess of Cornwall, in the will at all, the publication sensationally reports.
'Imagine if Meghan gets money, but Camilla gets nothing,' says the insider.
'That will sting.'
Charles' brother, Prince Andrew, is also 'livid', says the insider.
'He thinks his girls, Beatrice and Eugenie, are treated unfairly.'
The royal family is yet to respond to In Touch's report.