What is the ruling on a woman who entered into a state of ihram for Umrah while she was menstruating, then returned to her country without completing the rituals due to the continuation of her menstruation, and she did not know that it is impermissible to end the state of ihram before completing the rituals?

The woman is still in a state of ihram (definition) and must complete the rites of Hajj/Umrah (definition) by going to Mecca. If she is unable to, then she is considered to be prevented (muhasarah) and should exit ihram by slaughtering a sacrificial animal (hady). If she is unable to do that, she should fast for ten days. The woman in ihram must refrain from the prohibitions of ihram. What she committed out of ignorance carries no penalty, except for acts that caused damage, in which case a fidyah (definition) (expiatory payment) is due.