Should a woman who came from Yemen with the intention of performing Umrah, and experienced menstruation before reaching the Miqat, then stayed in Jeddah for a week, enter into the state of Ihram from Jeddah or from the Miqat of Yalamlam?

Ritual purity (tahara) is not a condition for assuming ihram. A menstruating woman can assume ihram and perform all the rituals of Hajj except for circumambulating the Kaaba. If a woman decides to perform Umrah after passing the Miqat while she is menstruating, and then intends to perform Umrah from Jeddah, there is no harm in that, and she should assume ihram from Jeddah. However, if she intended to perform Umrah when she passed the Miqat but did not assume ihram, she must return to the Miqat to assume ihram from there. If she assumes ihram from Jeddah (in this latter case), she is required to offer a sacrifice (slaughtering a sheep in Mecca and distributing its meat to the poor).