I’d say probably not, as I don’t think Reg 9910(g) applies to someone until you’ve made a decision to that effect – the idea is to ensure the decisions on the original tenant’s HB and the ex-non-dep’s HB are consistent with one another. Moreover, looks like you would not have applied Reg 9(1)(g) on the facts anyway. Therefore the daughter cannot be a non dep.
That leaves you with one club: apportioning the rent to achieve whatever outcome seems fairest. I’d suggest apportioning it in a way that leaves HB falling short of the full rent by the amount of the non-dep deduction that would have applied otherwise.
