All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
Given that this man is a non-mahram (marriageable) to her, then she must deal with him on this basis. The fact that he is blind does not permit her to do with him what Allaah has forbidden, such as him holding her arm or touching her, and so on.
Her mere company could be a reason for temptation for him, so all of this should be avoided. If he is blind, she is not. It was reported that Umm Salamah was with the Prophet and Maymoonah said: “Whilst we were with him, Ibn Umm Maktoom entered upon the Prophet and this was after we were ordered to observe the hijab (to screen ourselves from non-mahram men), so the Prophet said, 'Observe the hijab in his presence.' I said, 'O Messenger of Allaah, is he not blind; he can neither see us nor know who we are?' The Prophet said, 'Are you yourselves blind? Do you not see him?'” [at-Tirmithi]
After narrating the hadeeth, at-Tirmithi said: “This is a good-authentic hadeeth.” Some scholars classified it as weak, and some classified it as authentic as it was narrated by different chains of narrators. In any case, its meaning is correct.
Allaah knows best.