In Fate/kaleid liner PRISMA☆ILLYA, she is alive and is happily married to Kiritsugu. Kiritsugu and Irisviel are Illya and Shirou's parents. While they are constantly traveling abroad, she left Illya to Leysritt and Sella care.
In Fate/kaleid liner PRISMA☆ILLYA 2wei! she reveals to her daughters the truth about their birth and the Einzbern family. She tells them that there was once a ritual called the Holy Grail Wars in the Fuyuki City and Illya was made to act as the Holy Grail of the Fourth War. Kiritsugu gave her the choice between doing nothing or leave Einzberns and work to stop the ritual. They do so, causing the fall of the family.
Irisviel has a close personality the her Fate/Zero counterpart. She states that she is fighting to “preserve their daily lives” in her journey. Irisviel is very close to Illya and is aware of the power sealed inside of her. She seems to take a cunning pleasure in the matter of teasing her adopted son, Shirou, always joking about his "harem", while she even takes pictures of him when he doesn't expect it to try to sell them to Rin and Luvia. Oftentimes she comes off as overly carefree and ditzy, though she does have moments of being very wise and serious. Being aware of Caren's identity, she is first shown suspicious about her true motives to watch on her daughter and friends. Later on, she adopted Chloe von Einzbern after putting an end to the conflict between her and Illya.
She comes back home very often. According to her, the first two times were because of her mother's intuition and connection to Illya. When she does return, she brings many souvenirs for the family. She also seems to share the same dangerous driving habits that her Fate/Zero counterpart has, not caring about the state of her car and even going to the point where she casually kicks out one of the doors of the vehicle just to get out of it.
Fate/kaleid liner PRISMA☆ILLYA Edit
Irisviel is more present in the story than her husband. She is first directly seen at the end of Fate/kaleid liner PRISMA☆ILLYA when she comes back home to help Illya dealing with her problems. In 2wei! she is also seen with Kiritsugu overseas, telling him that she feels that Illya may have gotten in a troublesome situation in Japan. When she first deals with Chloe von Einzbern, she reveals that she is aware of Magecraft. Even though she is very familiar with the Holy Grail War ritual, she isn't aware of the Class Cards, confirming that the only similarity that they have with the ritual is the Servants classes.
During the fight with the Eighth Card, she finds Caren Hortensia in the nearest forest to the battlefield and ask her to explain what is going on with a serious tone. When Caren tells her that Holy Grail ritual has begun, she reacts with a shocked expression, saying that it's impossible to do it independently as long as she is there, but Caren responds that it may be a ritual different from the Einzbern's. After finishing their conversation about the current issue, she drives, searching for Illya and the vanished amount of energy that came from the top of the great cavern.
In terms of Magecraft, Irisviel seems to have the ability creation and forging of matter that her counterpart possessed. Even though she wasn't really seen using it more than once, the one time she uses it tu punish Chloe and Illya, she transforms her long and flexible wires into a weapon with the form a big human hand. It is strong enough break the ground apart and easily immobilize a foe.
She also has shared her counterpart's ability in reckless car driving.