'Why don't you be a housewife?'

Hi,

I got this situation from a sitcom: There’s a role-play in which every student pretends to be have a particular job. One girl doesn’t seem to be suitable for any job, so the teacher said: ‘why don’t u be a housewife?’. I wonder if this sentence is correct (I mean ‘don’t’ vs ‘be’).

Thank you very much.

‘Do’ and ‘be’ work fine together when ‘be’ means ‘act as’.