No sure if I missed anything but there is no information of who her father is. Just said it is an ordinary ninja.
There is information about him, albeit his name was never mentioned.
In Itachi Shinden: Book of Bright Light
“My dad died in Nine Tails’s attack.” .. “Oh! My dad’s not an Uchiha. My mom’s Uchiha. After my dad died, we came back to the clan, and I became an Uchiha, too,” Izumi told him, as if reading his mind.
“Is there a connection between your father’s death and the sharingan?” “Yeah.” Izumi sighed, and met Itachi’s eyes. Her own had returned to normal. “I was there with my dad when he died. He died right in front of me. He was protecting me. So I …” Tears ran down her cheeks. “It was like, if I just had more power, my dad wouldn’t have had to die … During the funeral, and the whole time after that, I blamed myself. ‘If only I had more power,’ I said.”
In one chapter, Second of Third Hokage says that Kagami Uchiha was a good and talented member from Uchiha's clan and says that he was the father of Izumi.
1Do you have a source to back this up? Jun 14, 2019 at 20:58
I just saw that on a memory of Hiruzen or Tobirama during the great shinobi war, maybe when the kages answer sasuke question's– L FJun 14, 2019 at 21:00
But this would contradict information on the LN that his father is not an Uchiha. Can you provide a source (specific chapter or episode) for verification purposes?– W. AreJun 17, 2019 at 1:16
@W.Are Maybe contradict, TOEJI Animation made this chapters by their own creative license.– L FJan 26, 2022 at 17:14