Are you talking about Lycoris squamigera?
They must have just faded by now. You can dig them up now or sometime this fall and plant them. The leaves should come up in spring.

I hope your mother in law realizes that they will take at least a year, maybe even 2 or 3 to establish before they begin to bloom in the new place.

Licoris squamigera should be planted shallowly in well drained soil and they sulk for a long time when disturbed.