Typhoid as a blessing
If someone approached a person and said, "Would you like some typhoid fever?" the answer would probably be a resounding no. But to Maryna, the fever is an inciting incident because it causes her to seriously consider the likelihood of death. She realizes that there is little to be gained through safety and comfort, because even the safest humans alive are not safe from death, and comfort only stops her from pursuing her dreams. She decides to take risks in a strategic way, banking on her willingness to work hard.
Maryna's persuasion
Maryna learns something about herself that she didn't know when she talks her family into moving to America. She learns that she is surprisingly persuasive (a good trait for an actress to have, one should think). This is revealed to her through dramatic irony in a scene that could be used as a case study for explaining why "dramatic" irony is called "dramatic." She doesn't know whether she will succeed or fail, but by attempting something earnestly, she gains insight into her own nature.
The irony of the farm
If the typhoid fever is ironically good, then the farm is ironically bad. They work together and work hard, but still, they can't establish themselves as farmers. For some in the family, this leads to full-blown, explosive conflicts, but for others, it leads to independence and success. For Maryna, it gives her a new opportunity to pursue her dreams, free from the duty that bound her to her community. She departs for good and fulfills her destiny.
The ironic actress
Maryna is a talented actress, but her suffering, resilience, and perseverance throughout her life (not in relationship to acting, but in general) makes her a phenomenon. She is the last great stage actress in the West, and she earns glory for herself in the true sense of the word. She plays characters with sensation and sincerity, because she is familiar with extreme passion and depth, because she is deep and passionate as a person. Her life was preparing her for her destiny all along, even when she couldn't see it.
The irony of fortune
In Poland, there was no fortune for her. In America, there is fortune somewhere, but she can't figure out where it is. She thought America was the kind of land that would reward hard work, but she pours herself into work to no avail. She disappoints her family. She witnesses her family disintegrating. In a way, she must have felt that she destroyed her family, and yet, all this circumstance allowed her an opportunity which she seized. The result was that she made an absolute fortune. The irony is that it isn't hard work alone that she needed; she needed to believe in herself.