According to Karlovy Vary International Film Festival's press release about 'Anthropoid' press conference, Anna Geislerová joins the cast:
Director Sean Ellis selected actors Jamie Dornan and Cillian Murphy for the lead roles, parachutists Jan Kubiš and Jozef Gabčík. One of the main female characters, Gabčík’s partner Liběna Fafková, will be played by Czech actress Anna Geislerová. Jamie Dornan’s partner will be played by Charlotte Le Bon.
And according to website SME Kultura's Anna Geislerová's character Liběna Fafková is Cillian Murphy's character Jozef Gabčík's fiancee.
Also Anna Geislerová herself talks about 'Anthropoid', Jamie and her character in the movie in a new interview with Super.cz which is released yesterday:
"It's a Czech-France-UK co-production. But I'm not Jamie Dornan's partner. I play the other person's, whose name is Gabčík, partner and he [Jamie] plays Kubis. So yes, I'm in the cast but he is not my partner," she told us. Also Geislerová said that she's looking forward to meet Jamie Dornan, who is also invited to festival.
Anna Geislerová's interview translated by us