Local Housing Allowance and shared care of children

I have a client who has a Residence Order stating that she and ex-partner have the children (aged 10 & 9 of opposite sex) on alternate weeks.  She and ex have CB & CTC for one child each. Client has 3 bed property & council are refusing to pay 3 bed rate because they say she only has one child evidenced by CB & CTC. She should qualify for the 3 bed rate now her daughter has turned 10. Does anyone know of arguments/case law that can be used to challenge this?

The difficulty is that the children are members of each household 50/50 in terms of time.  On that basis, as the law currently stands for HB/CTB, child benefit is the decider.  On that basis, I’m inclined to a view that the LA is correct to only include the child for whom child benefit is in payment for.

You could try and argue that the test for being a member of the household is a different concept to being an occupier for LHA size purposes, but I wouldn’t stake much money on the outcome.