Every blog has a sole owner and it is the person with the username account who registered the blog under that username account and associated email address. No matter how many blogs are created under any username account there will be only one gravatar and one primary blog that can be linked to that username.
You need to contact the blog's owner and have her act on this. They must be logged in as Admin http://en.support.wordpress.com/user-roles/#administrator under the exact same username account that registered the blog and purchased upgrades to renew them or transfer the blogs and the upgrades to another username account.
To transfer a blog from one username account A to another username account B they must first log in under the username account A that owns the blog you want to transfer to the other username account.
Then they add the other username account B as an Admin of the blog.
adding users http://en.support.wordpress.com/adding-users/
user roles http://en.support.wordpress.com/user-roles/
Then they A can use this process to transfer the blog to that username account B instead http://en.support.wordpress.com/moving-a-blog/#transferring-your-blog-to-another-user-or-account