Does a mother bear a sin for aborting her fetus in the fifth month despite her strong refusal, and what is the expiation for that, if any?

If the matter is as mentioned, then there is no sin upon the mother if the procedure was performed without her knowledge or consent. Abortion is permissible after the soul has been breathed into the fetus if trustworthy doctors determine that its continued presence poses a certain danger to the mother's life, in order to avert the greater of two harms, even if the fetus is malformed. However, the basic principle is the impermissibility of aborting a fetus after the soul has been breathed into it, except in cases of extreme and certain necessity that threaten the mother's life.