All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
Since your wife and her mother performed ‘Umrah on the next day as you mentioned in your question, then they are not liable to anything as long as they did not do any of the acts that are prohibited during ihram. These acts include removing hair from the head or the body by shaving or any other way; cutting nails; using perfume, after having assumed Ihram, in clothes or the body; and wearing gloves or a niqab (face cover). If they have done any of these acts, then they (not you) are liable to a expiation. The expiation consists of either slaughtering a sheep in the sacred precincts of Makkah and distributing its meat among its people; fasting for three days, even if separate; or giving charity to six poor people—each of them is to be given half a saa‘ (3 liters) of dates, barley, rice or what people eat. A saa‘ consists of four mudds (0.75 liters). A mudd equals two handfuls of a medium sized person.
According to the correct opinion of scholars:
If one commits any of the mentioned prohibitions due to forgetfulness, ignorance or compulsion, then no ransom is due upon him.
Allah Knows best.