Well you are right, but Technically by the 1983 Cannon Law any priest (Sacerdos) can and will have to impart the sacrament of penitence
Can. 968 §1. In virtue of office, a local ordinary, canon penitentiary, a pastor, and those who take the place of a pastor possess the faculty of hearing confessions, each within his jurisdiction.
and
Can. 986 §...)
§2. In urgent necessity, any confessor is obliged to hear the confessions of the Christian faithful, and in danger of death, any priest is so obliged.
now the term used in the original it´s in Latin, and Sacerdos refer to any one that insofar are any one to do holy work, including fray and nuns, So theoretically in case of grave urgence, live or dead situations, or complete isolated situations, a Deacon or even a Nun doing or taking the place of a community Pastor could and should give penitence and heard confession. And then he or she have to confess to a proper ordained ministry when the situations it´s resolved.
So a nun could hear confession but in a series of really improbable, but not impossible, situations
Is it possible that, something could happen that make those situations not impossible, but more probable? Or would that be ASB?