the shared folder on the server must be set to allow others on the network to write to them. When you mount a network shared folder on the client computer, you must mount it on the folder you have writing access to in order to wrote to them.
what are the permissions on the mounted folder on the client computer?. you keep saying "his","hers" and i dont know what computer is what ..i hope you know which one is the server and which one is the client.
i am currently talking about permission issues on the folder on the mount point of the client, make sure permissions are set to read, write and execute to owner, group and others