I get where you are coming from curious. And I most certainly do not agree in Allison being called chunky (or anyone for that matter). But I think discussion of her size is relevant, given the clothing. I can't comment for others, but I'm not judging her, regardless of whether she was a size 6 or a size 20.
I personally believe, based on my own size and that of people I know, that unless she had changed weight dramatically in the months before her death, she was probably around a standard size 12-14. And I think the clothes she was found in were her own. Even if someone else dressed her in the clothes she had on, I think they'd be pretty stupid to put her in someone's else clothes. Just doesn't make sense to me.