Benefts vouchers scheme to avoid the money being 'misspent' ?

Last year, in December, my LHA tenant did not pay her rent, I know damn well she kept it and spent it on her baby. Not this year though, The council are paying me every 28 days, her Mum is paying off the arrears at £100 per month.

I'm dreading when UC comes in, will she get the rent into her account again? I do hope there is still a way for landlords to get the rent paid directly.