POSITVE-NEUTRAL or NEGATIVE

What constitutes a POSITIVE sale on eBay? I received a NEUTRAL from someone yesterday (and you know that made me totally beyond crazy).
She said that the RALPH LAUREN pink snowsuit was too big for her baby.
NOW - let's start with the fact that all measurements are given in the description and I personally believe that the buyer should look at those measurements and be aware whether the item should work according to those measurements.
I have received items back (well, once) because the measurement was off by an inch. The item was received back with a smile because there is no other way. The buyer felt that I should have known that the 9 month Ralph Lauren snowsuit ran big. I do not feel that is reasonable - how would I know whether it runs big or small. Yes, if it had been my child's snowsuit and had been worn, I assume I would know whether it ran big or small. BUT my children are grown with babies of their own and I have at least 360 items listed - I can't possibly know whether any of these things run big or small unless they were mine and I had worn them. This was BRAND NEW and the funny thing is that I happen to know that generally Ralph Lauren runs small.
She receives the beautiful pink snowsuit (and it was beautiful) and discovers that it is too big for her little doll! That can happen - but does that mean you leave NEUTRAL feedback? I would have gotten in touch with a seller if I was unhappy with my purchase. I have bought many many things on ebay and overall have been very happy with my purchases. BUT when I have not been happy I have resolved the issue with the seller. I believe that the seller should be made aware of any unhappiness before leaving anything but a POSTIVE feedback. Feedback is very important and even though NEUTRAL does not effect your overall number-it does effect what people read about you.
So, what constitutes a POSITIVE sale?
The item was shipped immediately upon her payment. It was wrapped and packed carefully and I'm sure it arrived to her in Australia in perfect condition.
The item was EXACTLY as described - photos were clear and item was exactly as shown.
Measurements were given and item was in fact, described exactly. If it didn't fit her baby, should that make her feedback NEUTRAL?
I don't think so, but I would like your opinion. My listings clearly state that if for any reason you are unhappy with your purchase you are more than welcome to return for a full refund (minus shipping if item was as described).
You can see that I am very upset about this. I emailed her and she was very offended - saying that now she wishes she could give me a NEGATIVE. I truly love ebay and am very lucky that 99.9% of my buyers are fabulous - but I guess I take it too personally when that .1% acts up! Tell me what you think and check out my listings.

http://shop.ebay.com/ilovemygirls3/m.html?_trksid=p4340.l2562