The Duchess of Cambridge is "mediating" between Princes Harry and William.
The brothers continue to have a strained relationship at present following the Duke of Sussex's bombshell interview with Oprah Winfrey and his and his wife, Duchess Meghan's decision to leave the royal family, but Catherine has been "doing the best she can" to be "peacemaker".
Her uncle Gary Goldsmith said: "Everyone is astonished. He wanted to step back and protect his wife, now he’s charging in.
“It's an attack on the family - why do it? If you want an easy life, work it out privately and have a conversation respectfully. Don't air it in public, it's really hurtful.
"The harsh truth – in my opinion – is that if Harry doesn’t get a grip and stop this self-indulgent episode, there will soon be no common ground or relationship to rebuild.
“But if anyone can bring peace to the royals, Kate can. Kate is a brilliant arbiter and peacemaker. Every bone in her body is about making friends and doing the best she can ... She’s trying to mediate [between them]."
And Gary - who is the brother of Catherine's mother Carole Middleton - says the Duke and Duchess of Cambridge were a "strong unit" alongside Harry and she wants to ensure things end up being right.
He added to Closer magazine: "You could see at the funeral that Kate was there trying to make peace, bringing the brothers together.
"Harry and Kate were great friends, they were a trio with William and a strong unit. Family and relationships are everything to Kate - she’s very nurturing, she wouldn’t like that [rift] happening and she is trying to look after her husband and do what she can to make things right."