The meaning of bliz/bliz has finally been figured out, thanks to the
help of a couple of Genners and Facebook readers. The word means
"twins" in Russian, which makes sense since the names were >from birth
records.

"While looking at a list of names >from the Kiev Rabbinate, a word
translated as "blyz" was used:

Briskman blyz. Shakhno and Reyzel
Barbier blyz, Solomon and Chaya/Haya
Boltny blyz. Rosalia and Sara

Marilyn Robinson
Florida