There are many reasons she should file unless, of course, has something to hide. The editorial spells them out, such has her directly benefiting form husband's tax policies.
Freepers, including me, wanted Kerry's wife to release her tax returns and eventually she did some of them. I do not recall anyone arguing that she should not.
I'm still waiting for John I Served In Vietnam Kerry to release his records,but alas my beard is growing gray from all the waiting.