Hi Jonathan,

MataJi was Prem Rawat's birth mother.  Shri Hans and MataJi had four sons.  Prem's brothers from the same parents are: Bal Bhagwan Ji, Bhole Ji, and Raja Ji.   Prem is the youngest.  This has never been in dispute, but it's true that premies have cultivated many myths over the years.

Hope it helps!