When you see a 「は」 in the following structures, it emphasizes the preceding verb, adjective or noun.

"[連用形]{れんようけい} (conjunctive form) or the て-form of a verb + 「は」"

 

"連用形 of an adjective + 「は」"

 

"Noun + 「で」 + 「は」"

「ユルして + は + いただけませんの？」 fits the first pattern above and in the phrase, the speaker is subtly adding emphasis to her petition for mercy. Without the 「は」, she could sound pretty arrogant. She could sound like she takes it for granted that she will be forgiven.

When you see a 「は」 in the following structures, it emphasizes the preceding verb, adjective or noun.

"[連用形]{れんようけい} (conjunctive form) or the て-form of a verb + 「は」"

"連用形 of an adjective + 「は」"

"Noun + 「で」 + 「は」"

「ユルして + は + いただけませんの？」 fits the first pattern above and in the phrase, the speaker is subtly adding emphasis to her petition for mercy. Without the 「は」, she could sound pretty arrogant. She could sound like she takes it for granted that she will be forgiven.