The irony here is that Melania lays it on rather thick about how she's nothing like the people her husband wants to boot out of the country. Let's call it her 'I was legit white immigrant' tour.
Here's the problem, as both TPM Readers JSK (immigrant) and PG (immigration lawyer) noted to us in emails: the set of circumstances Melania describes makes it almost certain that she was in the US on travel/visitor visas rather than a work visa. If you're on a work visa you don't have to keep traveling back and forth to get your visa renewed. (The Politico article goes through the technical names for these different kinds of visas.)
There is a possible exception: very high profile athletes and models can get a kind of visa which allows them to visit the country and work for a short period of time. But Melania wasn't in that echelon at all. She was one of many models trying to get a start in the business doing mainly catalog work.
The upshot is that Melania was almost certainly working in the US illegally. And every time she returned to the country and passed through immigration she would have had to have committed fraud by saying she in the US to visit rather than work.
In theory this would make her subsequent Green Card and even citizenship suspect, based on visa fraud earlier in the process.
It is only fair to say that based on our reporting this sort of illegal work was rife in the modeling industry at the time. This wouldn't have made her a particularly egregious example. But then few of those women are now married to a man who wants a zero tolerance policy that would lead to the expulsion of 3% of the current US population.
So if you're inclined to snark, Trump's third wife was an 'illegal'. Even her status in the country today could, in theory, be suspect.