Is it obligatory to assume ihram for Umrah from Yalamlam for someone coming to Abha from America via Jeddah, or is it permissible to assume ihram from Jeddah? And is it permissible for the wife to postpone Umrah and go to Abha after forming her intention in America, then return to perform it in mid-Ramadan, or must she remain in Makkah until she performs it?

There is a difference between intending 'Umrah later and intending it during the same journey. If the intention is for the same journey, then one must enter into ihram when parallel to the Miqat by air, and it is not permissible to delay it until Jeddah. Entering into ihram from the Miqat is obligatory, and whoever enters into ihram before the Miqat, their ihram is valid. However, if the intention for 'Umrah is for a later time, then entering into ihram is not required when passing the Miqat. As for a menstruating woman, her ihram and all other 'Umrah rituals are valid, except for circumambulation (tawaf). She remains in her state of ihram until she becomes pure and completes the 'Umrah, and it is permissible for her to leave the Haram while still in ihram.