Your answers are correct, too. If they were marked wrong, report it. The reason behind this is that two different verbs are used. In Mayo and Donegal cluin is used. In the rest of the country Clois is used. They both conjugate the same in the past tense, but are different in all other tenses. Both are correct, however.
I'm going to answer my own (missing) question here, even though my previous, very lengthy comment to my own comment was mysteriously deleted after my last reply to self.
In short, this sentence confuses me because 'the woman' is definitely not in the nominative case, not even as a subject compliment, which would be reflexive.
In English grammar, 'an bean' or 'an bhean' (the woman I hear) is a direct object falling squarely in the accusative case (subjective), leaving only the genitive case (possessive) and vocative (if you consider the vocative case, to be a case) to remain unchanged, or un-lenited.
In other words, following the 'tips' using English grammar terminology, and extending them to the accusative case, 'an bean' would almost always be lenited.
But looking back at some helpful comments people made when I commented on a similar issue I had, (thank you user, whose name I can't look up until after I post), Irish does have more cases than English does and it distinguishes between two types of noun/pronoun cases that would be called accusative in English. Irish uses the dative case, and generally speaking, if 'an bean' or any feminine noun is in the predicate of a sentence, and is not the subject compliment, i. e., she hears herself, then it is not nominative, but accusative. But if it follows a simple preposition, like, 'I listen to the woman,' rather than, 'I hear the woman,' then it is in the dative case (in Irish) and therefore not lenited. So, I now know of instances when 'an bean' would not be lenited, and am subsequently less confused.
Read this, because they say it better: https://www.duolingo.com/comment/11255240$comment_id=13972190