That's assuming she actually got a work visa.
I'm not an expert nor do I claim to be one but since content creation is considered being self-employed, that should rule out an L-1 (intra-company transferees). I'm not sure how you could argue what Em does demonstrates "extraordinary ability in arts, sciences, or business" (which is the criteria for an O-1). And I don't know how broad the qualifier for "specialty occupations" is for an H-1B visa is, so if she got a work visa, this is the only real explanation.
Unless her work visa was for a different job, of course. Em may have had her share of big spenders in her chat, but was she really making enough money to support her lifestyle living in LA by herself? Yes, she has 90k followers and she gets her share of sponsored streams as a Twitch Partner and whatnot, but if you look at her metrics, she hasn't experienced significant growth since moving to LA outside of the incident with Neon. At least, not growth comparable to say Tay or Kara in the same time period (at around 80k followers -- which granted, isn't the most fair argument given differing trends, states of the economy and of course, the boon that the Covid-19 pandemic was to the content creation game which is especially relevant when comparing Em to Tay). Makes you wonder, is all I'm saying. Is content creation really Em's sole source of income? Or do her parents help her pay her rent? I'll come back to that in a minute.
There's also the possibility that it's not a work visa at all. Again, I don't claim to be an expert, but I do know the J-1 visa is for exchange visitors, scholars or interns. Even the F-1 or M-1 are visas given to academic or vocational students. And of course, the E-2 is a thing (individuals from countries are allowed to live and work in the US while heavily invested in a US business) as is the K-1, which allows a foreign national to enter the US to get married.
While Em's marriage does seem awfully convenient, I don't think it works in the sense that you could come to the US looking for a husband. I think you have to be engaged prior to applying for the visa. But who knows, she could have been two-timing Thunder for years for all we know. It's a possibility. Em's loyalty has been questioned with some very compelling arguments in this thread, but I'm going to assume she didn't get a K-1.
And while I do seem to remember there being numerous conversations about Em's parents being very well off, I don't think they could get her an investment visa like an E-2.
However, sticking with her parents' money, is it crazy to assume that she moved to LA with the intention of also going back to school? Well, she's what, 29? I doubt she's going back to school to chase a new degree. And her pre-law studies (which, if memory serves me correctly, she didn't even finish?) were all in Canada, which of course practices a different legal system than the US does. Not that there crossover or similarities don't exist, but I would say a student visa is also unlikely.
So, does anyone recall whether Em said her visa was temporary or permanent? Because I don't. I don't know why she would specify, but I don't know why she yaps about a lot of the things that she does and we've established she isn't the most honest streamer on the platform, either.
Why do I ask? It is possible to obtain a permanent family-based visa for immediate relatives and extended family members of US citizens and green card holders. I have no idea what her dad does, but if they're well enough off and he does business in the US, it wouldn't be surprising for him (or her mom, maybe? She could be a boss bitch, I don't know) to have dual citizenship.
The answer's likely in that incoherent rambling of mine, somewhere. We'll likely never know, but speculation can be fun.