It may be possible to confirm family relationships with Unknownmother by comparing test results with other carriers of her mitochondrial DNA.
However, there are no known mtDNA test-takers in her direct maternal line.
It is likely that these autosomal DNA test-takers will share DNA with Unknownmother:
Max Heffler :
23andMe, GEDmatch M359165 [compare] +
AncestryDNA, GEDmatch A266036 [compare], Ancestry member Max_Heffler +
Family Tree DNA Family Finder, GEDmatch T552284 [compare], FTDNA kit #2805 +
Autosomal DNA Test, GEDmatch M177048 [compare]