No offense, but if this time and the last time she was on hiatus was due to her anemia, I seriously don't want her to debut.
I don't know what type of anemia is it. I would understand if it was sickle cell anemia or something more hard to treat, but if its due to iron, vitamin B12 deficiency of something along those lines, girl needs to learn how to hold on to her health instead of letting all drop again. One's health should aways be first.
I just want her to be able to debut without having her have constant temporary leaves due to her health. It will affect the group, especially if she's becomes the leader (she is now the second oldest KSS btw). Like I said, I don't know what type of anemia she has, so I don't know if its something that can be controlled medicine or a special diet. If its something that can be managed, she should try her best so it doesn't lead to severe anemia for a long time (rather than in less than a year).