A couple of ideas to consider that might help:
*You could request to be on the trusted list of the profile's manager (added: that would be if your already a member). Have you contacted them yet to let them know you are a relative? Just send them a message either on their page or by private email.
*Also you could post this information on the profile itself so that it doesn't get lost in the future and that the others interested in this profile can find it easily. You could add it as a comment on the right side of the page. Or if you have a source post it on the biography portion of the profile. That would also be a great help in establishing factors to make the change on the profile itself.
Oh, I forgot to ask, are you already a member of WikiTree? If not, you could join us, its free, then be a part of the collaboration of the family tree. We would love to have you!!