It's really ambiguous what they're talking about or what they even mean. Here are two things that could both be described as, "Forcing Tibetan children to kill their parents."

• A Tibetan soldier volunteers to join a war, and through sheer chance, they learn that their parents are fighting on the other side of the battlefield. They ask to leave the front and their CO refuses - technically, they've been forced to kill their parents.

• A communist agent abducts a family in the dead of night and hands the child a gun while putting a knife to their sister's throat and telling them if they don't kill their parents, they'll be killed, along with their siblings. This happens systematically across Tibet, and only Tibet.

They could be referencing the Cultural Revolution. A lot of shit happened during this period, including what you described. But to my knowledge, the struggle sessions and such were more the actions of the Red Guards, who were student led paramilitary groups, not the same as the People's Liberation Army that went into Tibet.

So like, what they said was, "the liberation army forced Tibetan children to murder their parents," but, what actually happened (so far as it's possible to connect that claim to anything in reality) was that the PLA failed to maintain control (although they did eventually succeeded in suppressing them) against young radicals denouncing their parents and subjecting them to public humiliation (the Red Guards also committed all sorts of atrocities during this time, I wouldn't be surprised if there were cases of children killing parents but I'm unaware of any specific cases). Which happened decades after the PLA went into Taiwan, which wasn't (to my knowledge) really a main area involved in the chaos.

And that's why I asked for a source.