As someone who had the original Long Xiulan's memories, Iris could sense the similarities between the original and her eldest twin son more intensely than others. It was like seeing another version of herself through her son, even though that self wasn't even her own but the original Long Xiulan.
Like what Jin Liwei said just now, Little Mochi was also making her appreciate the original Long Xiulan. Even though she, Evelina, had already long taken over the life of Long Xiulan, the original's presence could still be felt in many different ways. The most noticeable was in her eldest twin son, Little Mochi's personality.
Iris and Jin Liwei were both determined not to make the same mistake as Wei Lan and Long Tengfei. Given what happened to the original Long Xiulan with her personality, they already had a clue what to do in order to prevent Little Mochi from following in her footsteps.