Iris didn't realize how much her lost not only affected her and Cane, but also the people around them. She failed to realize that, because they tried to act as normal as they could in front of her, too afraid to shake the boat.
However, in reality, the death of her babies affected the people that cared for them too.
Ethan watched how Aliana lost her baby, he was there when she had to go through her depression during the slavery, it was hard and cruel. Misery was an understatement to picture what actually happened during that period of time.
And when Iris lost her babies, there was a moment where Aliana spiraled down, though she didn't say it, but Ethan could see it.
After all, he was there when she lost her mate and her baby. The excruciating pain in her scream from across the cell from him, while he couldn't do anything and witness how that beautiful woman crumbled down.