Her matches are mostly adoptees, but that doesn't necessarily mean she was. I would imagine a large percentage of Korean Americans taking these DNA tests will be adoptees looking for birth family, since huge numbers of Korean babies were adopted in the US. She could have been an adoptee but could also just be from a Korean American family, since a lot of Koreans moved to the US too (778,899 between 1941 and 1998). She was likely born 1965-1985 based on her age estimate. Towards the earlier part of that timeline it was mostly mixed Korean babies of US servicemen who were being adopted in the US, and then it really took off in the 70s and 80s, reaching its peak in 1985. Korean families moving to the US were common from 1965 onwards because of war.
Interestingly (and tragically) if she was an adoptee, and was adopted prior to 1983, she may have had difficulty. Parents often didn't apply for citizenship of their adopted children and many institutions failed to grant it because the system didn't recognise international adoption. This wasn't rectified until the Child Citizenship Act of 2000. Those born 1983 or earlier were adults by the time of the act going through and were often left without citizenship, unable to access resources and in danger of deportation. About 20% of the total adoptees from Korea don't have citizenship - about 40,000 people. There have sadly been cases where these people - who have grown up in the US, only know life in the US, do not speak Korean - have been deported. I would think that having no citizenship could potentially be a trigger for taking her own life (although it's statistically unlikely that she's one of those 40,000 without citizenship).
My first thought was nail salon tech, most of whom in the area (longtime area resident) seem to be Korean or Thai, generally speaking.
Large groups of families would own and work several throughout New England and it is a mostly cash only business at ones I frequented.
The ladies all dressed like the description, year round, and seemed to be unfortunately a bit interchangeable and expendable to the male relative (typically ) running shop. I rarely saw same techs twice as they rotated among the extended family group shops in area.
If I had an early morning appointment I'd see a white van pull up and drop a whole load of women exactly as described,down to hair length and ponytail, of varying ages off to the shop.
I don't know but always presumed many are illegally in US (overstay tourist visa) which may be another reason for family not to report a missing relative, especially an extended relative perhaps sent to be used for shop labor.
MOO and purely conjecture based on own observations and experiences.