She doesn't work for any particular person or company, her job doesn't require work permit as far as I can tell, she holds website for individuals even outside canada and yes she's been filing tax even while out of status and she haven't had any issues so far with that.Does she do any work for a person or company in Canada?
Has she been filing with CRA, even though she is out of status?
She can work remotely for a person/company that is outside of Canada and does not remunerate her from within Canada. This type of work does not require a work permit as it does not compete with a Canadian citizen or PR in the labour market in Canada.