There is no obligation in halacha for women to bear children. If she is honest and open about it, it is fine unless there is some dishonesty involved. There are a multitude of reasons and people should be understanding. if she remained unmarried or married to a man who is unable to bear children, it really is no problem at all. That being said, it would be an aveirah, i believe, if she married someone and prevented him from having at least one boy and one girl even if she was open about her feelings. But there may be “wiggle room”, not sure. Lmk if anyone has info about this scenario, halachally speaking.
As a side note, yes it is a “blessing” but the long process of it was originally instituted as a punishment from Gan Eden.
Regardless, put downs, judgey attitudes and loshon hara are always inappropriate.