Sharing Our Innermost Thoughts

Can someone advise me what to do my ex friend which i was very close to her , we recently have some miss communication which eventually lead to break our friendship she doesn’t not want to be friends with me ,understandable before when everything was good between us I promised her grandma that I will come and meet her because me and her grandma share same hometown , she said me to visit her, now she is very ill and I think it’s difficult for her to survive , do you think that I should ask my ex friend to allow me to meet her grandma once ? Because I promised her and I will be regret if I don’t? ( please suggest me )