Why did Doğa's mother commit suicide in the series Can Borcu?

The series Can Borcu has started on the atv channel. One of the primary events that forms the story of Can Borcu is the suicide of the woman who was Mehmet's wife and Doğa's mother...

The mother committed suicide 6 years ago, on the very day of Doğa's birthday. Doğa was only 10 years old at the time... And it was Doğa herself who found the body...

Doğa feels the void of a life without her mother. She does not know why her mother committed suicide and wants to find out. Over the years, Doğa has come to see her father as the reason for her mother's suicide. The thought formed that 'If her father hadn't done terrible things to her mother, why would her mother commit suicide?' For this reason, her relationship with her father is strained. She even blames her father, Mehmet, for her mother's death.

In the first episode of the series, we saw from a conversation between Mehmet and his colleague Sude that they are hiding a truth about the mother from Doğa.

Later, we learned that Doğa is not actually Mehmet's daughter. While Mehmet continues to hide the truth from Doğa, he tells others that the reason for the suicide was that the mother could not bear this burden.