I need to check the sources more carefully, but I'm reasonably confident that she is Malka Ashkenazi.

I need to check the sources more carefully, but I'm reasonably confident that she is Malka Ashkenazi.
Well, I just checked, and it isn't hard to identify the house of R' Abraham Abbish Ashkenazi of Brody and his wife Malka Ashkenazi in Brody in Gesher Galicia's database (it's house 1405, FYI), and sure enough, 'Isaac Cohn from Warschau' seems to have had one of his children there (mothers' names are not mentioned in Brody birth records from that era): Hudel. (All other Kohns from Warsaw in Galicia are from the same family, by the way.)