Their Relationship
Setsuna put on the biggest show for Kakashi. She made him feel loved and seen. Bombed him with love, and then one night in April, she took a pregnancy test and told a still rather young Kakashi (19) that he'd be a father. At first, he was very panicked, but she reassured him he could take care of a child and that he wouldn't be alone. Little did Kakashi know, it wouldn't be Setsuna.
She continued to put on a show for Kakashi, but secretly became disdainful of him for the simple fact that he was a man and he was powerful. She had no desire for the baby growing inside of her, and had no qualms abandoning the child. Though a tiny part of Setsuna knew the child didn't do anything wrong and would need someone in its life. Instead of leaving Kakashi completely without help, Setsuna employed the aid of Danzō to bring back Sakumo Hatake, who'd been dead for about 14 years prior.
Danzō thought it was a brilliant idea and helped Setsuna bring back Sakumo. Danzō's purpose was the wood kekkei genkai he stole from the First. The wood infusion into the clay golem Setsuna created would allow for Sakumo to live a long life, which usually didn't occur due to the lack of wood users.
At 40 weeks pregnant, Setsuna and Danzō would work together to bring Sakumo home. She performed the jutsu with a strange level of ease, although ended up exhausted and even weakened from it. Without Kakashi's knowledge, they were able to get Sakumo back to the Hatake residence and into a bed, and that's when Danzō left Setsuna alone.
On January 31st, Hatake Tsukiko (Later, Tsukiya) was born, and Setsuna faked her own death. The only person who knew the truth of what happened was Danzō. Setsuna left Kakashi, Sakumo, and the baby, and went to live freely. After recovering from giving birth, of course.
