Why did Lara's mother attempt suicide?

In both the book and the movie, Lara's mother attempts suicide because she suspects something is going on between Komarovsky and Lara, however in both sources it is made clear that these are suspicions and she doesn't actually know. The novel mentions that Komarovsky had been leering at Lara for quite a while, and Lara noticed this -- surely her mother did also.

In the film, in the restaurant scene, we are told that Lara's mother apologizes for having such suspicions; in the novel, she tells other characters (not in the film) that her suicide attempt was based on suspicions that turned out not to be true. Of course the audience (or reader) knows they were true.

She was dependent on Komarovsky for both business and financial support, and the prospect of losing this, and perhaps having her daughter disgraced, might have been further impetus for her actions.

In the book there was a lot more going on with the political events of the time and Lara and her mother had moved into a hotel in fear of their house/shop being attacked on account of an uprising that was happening, and Lara's mother's suicide attempt takes place in the hotel. Lara is also shown in the book hanging out with revolutionary friends (Pasha and another guy) so her mom could have been motivated by fears for their safety and future in addition to the personal reasons.