i doubt muchly if you can legally rent of your mum and dad and get HB paying for it
it screams SCAMMMMMMMMMMMM. to any reasonable HB oficer who will be thinking - eh up chuck!
the reality is the rental agency willg et someoe else to rent it
Miss smith with be back living with parents
Mr smith still gets his mortgage paid/covered by HB rental income
the only loser is Miss smith.
and she wouldbe entitled to HB in the house next door if its not owned by her dad.
all in all - who gives a shit. HB money would be paid out to Mr smith anyway the only loser is daughter smith and BF and baby - who have to suffer cramped living until some other (maybe scum?!) landlord says "ok my property is shit live here whilst i get your hb to cover my mortgage!