Does sexual intercourse invalidate Tayammum performed by a woman after purification from menses for minor impurity?
Chapter on Tayammum
Al-Mughni
Book of Purification
Primary text
If a woman performs Tayammum after emerging from menses, intending it for the minor impurity associated with menstruation, and then engages in sexual intercourse (Janabah), the intercourse does not invalidate her purification for the original minor impurity. This is because sexual intercourse only necessitates major ritual impurity (Janabah), and the ruling pertaining to the previous state (minor impurity purification) remains.
Supporting text
Ibn Aqil suggested that if every prayer required a specific Tayammum, then every sexual intercourse would require its own specific Tayammum, but the former opinion is considered more sound.