You’re absolutely right, called Martyshka (little monkey) same as in the book. As I was searching for material on her on Google I came across this interesting article: https://przekroj.pl/en/society/the-stalkers-daughter-renata-...

I'm reaching the conclusion that the Russkies just have a decidedly non-Western idea of femininity; hell, they used to seclude upper-class women in something called terem until the 17th century. Makes me half suspect Russia is a crypto-matriarchy and behind the scenes things are run by Putin's mom

The Żuławskian "evil woman" (Szamanka, Possession) is just so much more interesting as a character, as well as in terms of what her character implies about the world that made her as she is, than the Tarkovskian "mother-martyr" (and her imago form, the "maiden-miracleworker"). One is an incomprehensible embodiment of the most tragic and poetic traits of the individual, the other a temporary personification of an impersonal Motherland; so, besides different attitudes to womanhood, they also demonstrate vastly different views of personhood and the role of the individual in the grand scheme of living nature. It could be an artifact of the respective authors' personal upbringings and experiences - but as the Writer in Stalker explicitly notes, an author only becomes influential by virtue of reflecting something essential about their audience (which in this case would be initially limited to the respective ethnolinguistic communities).

Now contrast with the overarching message of contemporary Netflix-and-children style cinema. Absolutely fascinating! And quite important too - though nearly impossible to discuss.