AFAIK, it wasn't an arrangement she'd been in for a long time. I doubt she'd hit the six month point, and had been hoping to secure a visa to stay in the country legitimately.
Ack.. that's just incredibly poor judgement. If you have to lie to the officials when entering the country, you really shouldn't expect that a closer look later on is going to get you a visa - as soon as they discover you lied about it you're done for.
It's pretty common to lie to border agents. Both US and Canadian agents themselves have advised me to do so in the past. Ticking the "Have you been on a farm?" check box triggers a compulsory search for seeds (both smuggled and inadvertently stuck to your shoes). It is time consuming, and they know it to be a fruitless waste of time.