My wife and I are Orthodox Jews addicted to the Perry Mason of our childhood. We couldn't resist watching Hallmark's presentation of levirate marriage, or yibum, but never expected we could stomach more than 20 minutes of it.
The writers and directors certainly get credit for coming up with an original plot device to create romantic tension and resolution. This is Hallmark, after all, and we didn't expect all the dramatic unities to be observed, but we were pleased at the overall high quality of the research, writing and acting. There are Orthodox men who make a living outside the rabbinate, and non-Orthodox Jewish men who aren't cardiac surgeons, but avoiding these clichés might been too distracting.
The mystical / romantic motivation was never made quite reasonable, but much worse was the simple fact that marriages religious and secular require sexual consummation in order to be valid. The whole point of yibum is that the wife should get pregnant with her brother-in-law's child and therefore continue her dead husband's family and name. Such a beginning would have ruined the plot and perhaps run afoul of Hallmark's standards and practices.
One may quibble about this or that presentation of Jewish religious practice, but on the whole this movie did a good and conscientious job with remarkable few cringe-inducing mistakes. In the end it worked as a romantic comedy/drama which held our attention to the end.