At the end of the film Arrival (2016), what does Ian say to Louise when she asks him if he would repeat his future?
When packing to leave, Ian admits his love for Louise. The film closes as they discuss life choices and whether they should change if you could see the future. Louise sees a vision of Ian as the father of her daughter. Her vision continues with Ian asking her, further into the future, if she wants to make a baby. Louise sees herself replying "Yes," wanting to share a short time with her future child rather than prevent her from ever existing
From Wiki : https://en.wikipedia.org/wiki/Arrival_(film)
Louise accepts her future regardless of what she has seen in her visions. Ian and Louise express their love for each other and decide to start a life together. They even decide to have a child. But here's the catch.
Ref - Arrival explained:
This simply means that Louise has seen a future where Ian and her fall in love and have a baby. She also knows that her daughter will develop incurable cancer. She understands the pain of all of this. But she still chooses to have Hannah. But what Louise perhaps does is that she keeps that a secret from Ian. By the time Louise does tell Ian about the cancer, it is too late. Hannah is destined to die. When Ian finds out, he's unable to forgive Louise for having a baby knowing well that she is going to die of cancer at a young age. In one of the visions into the future you hear Louise saying that it was her fault Hannah’s daddy left.
While Louise knows about her future daughter will die of cancer, Ian is not aware. So he accepts his future with Louise not fully knowing what is in store. So they do start a life together, but appears to be that they separate.