I think you could get an 'older' person looking for some extra cash rather than a 'student'
I also think as its a regular thing you can set your own terms, ie if you want cleaning too specify it in job description
if I were you I would look to get 2 or 3 people so you aren't reliant on just one but have a pool of people to choose from should one of them be sick or unavailable
also if you get someone through a private ad, see if you can do a police check and certainly pick up references