Is it permissible for a pregnant woman during her waiting period ('iddah) to remove her mustache?

The waiting period (iddah) for a pregnant woman ends with childbirth, not after a specific number of months, whether the waiting period is due to divorce or death. If the iddah is for a revocable divorce, she is not required to observe mourning (ihdad). If the divorce is irrevocable, the preponderant view is that she is not required to observe ihdad. However, if the iddah is due to death, she must observe ihdad. It is not part of ihdad to refrain from removing what is permissible to remove for cleanliness, such as trimming nails, plucking armpit hair, and shaving hair. Shaving the mustache for a woman is recommended, and some Maliki scholars have deemed it obligatory. Therefore, a woman observing iddah due to death is not prohibited from removing her mustache.