The brand of shirt she's wearing, "Pascal Tex", seems to be extremely rare in the US, so much so that most of the Google results are about Bayonne Jane Doe herself. You have to search for it in quotes and then add the word "clothing" for any relevant results. The top result is the company's Facebook page, which says the company is based in Syria. Next is ImportGenius, a website that tracks shipments; the info I can see is limited due to a paywall, but it says there are only 6 deliveries for this company, possibly ranging from Nov 1 2006 - Oct 27 2019, although it also says that the company profile was last updated on Nov 10 2007. Details of one shipment are shown, also on Nov 10 2007 (maybe that's the most recent); Bayonne Jane Doe's remains were found a few weeks earlier. So there's a good chance that the brand was only sold in the US for less than a year before she was found, and possibly ceased shortly afterwards, which would narrow the window of when she died. The shipment of 461 pieces of clothing was delivered from Cairo to 64 Hobart St, Ridgefield, NJ (now a tennis court), which is only 19 miles from where she was found. (Coincidentally, one of the two people connected to that address also has a prior address on 21st St in Bayonne, blocks from the remains.)
I'd be willing to bet money that she didn't come from "anywhere in the Continental US"; she was local.