What should she do?

Honestly, Im getting really bad vibes about this guy. I'm not being judgemental about him or his situation, but just reading this gave me knots in my stomach. I think your friend should stay put.  If it is true love, it will stand the test of time and she can move when he has some more stability.

I second Tyesmommy, I have the same instincts about him.

Just an idea...break things down to make it simple. Means at least she has to answer herself just one question:

Am I more lucky spending my time alone or am I more lucky beeing with the guy?

Everybody knows Luck and happiness can't be paid with money. And by the way, if you ask yourself this question and if you feel more lucky spending time without your couple, don't be selfish and lazy, think about splitting.

Excuse me if this sounds a little weird, I promise in my native language it really makes sense and I can better explain it...

I'm not familiar enough with the Immigration laws here in the US to say for sure but it sounds like there are some extenuating circumstances in his situation other than just the lack of a legitimate visa. Having someone permanently deported that was not brought here of their own volition (I'm assuming that at 7 ys old he didn't make the command decision here) and has remained for a good long time barred for life based only on lack of a visa seems pretty harsh to me. Wonder why he was deported in the first place - what suddenly brought the lack of a visa to the attention of immigration officials to begin with. I don't think there's a big push to oust the brits at this time, so something else must have brought him to their attention.

Obviously we don't have enough facts to make a really informed decision, but I think overall it sounds to me like she would regret the decision to just give up everything and up and move to a different country - a totally different life - to be with this person. If that were her gig she'd probably be in Greenpeace or a missionary or something rather than a manager in a pretty comfortable settled lifestyle that is surely radically different than what she's likely to be confronted with if she makes that decision. But love is blind to these things, so they say, so maybe I'm way off. Maybe she's miserable in her current situation anyway.

If not though, how 'bout this option: He comes back here to be with her and picks up some semblence of the lifestyle he apparently so desperately misses. Not directly of course, but say he goes into Mexico or Canada (flies, sails, swims, whatever it takes) - and Canada's probably the better choice here - then moves back across the border from there. Some identification modifications or at least falsified documents might be wise for these steps. Sure it's risky; but those are small risks for a huge gain right? We're all comfortable with that here anyway. People do this sort of thing all the time for all kinds of reasons; some of them pretty petty. The chance to consummate the love of your life has gotta be somewhere near the top of the list of good enough reasons for it.

Maybe then, and with a little creativity,  he will be able to resume a more productive and fullfilling lifestyle and not have to wrench her from hers. Of course, with the economy and job market the way it is, he will be facing an uphill battle with this. If it doesn't pan out for him in the job front or just drags on at a slow crawl, Lips, you may need to teach one or both of them the dark art of bonus whoring. 

Well, I have found that be it female or male. If they have their heart set on the "Love Interest" you can talk till your teeth fall out. Just tell her "I don't believe this is a good choice" and let her go on with her life.

Lord knows we've all tried to steer people away form what we believed to be bad for them, but rarely was it they listened.

Gene is right, it's HER life and you can't talk her out of anything she has her heart on...she most likely wants affirmations from you and others that what she wants, is the right thing. However, the fact she even questioned following her heart means that something doesnt sit quiet well with it in her head. All you can do is state your honest feelings, reassure her you love her no matter what she decides, and sit back and see what happens.