She wasn’t a ‘packing girl’ and even if she was being forced to quit your job in any circumstance is stressful. I get that she doesn’t want her name associated with Polly which is maybe why she was directing her anger here. If you google her name/the company name this thread might pop up which isn’t the best PR.
I think you’re all being quite unfair, she’s more than within her rights to be angry and CLEARLY doesn’t agree with Polly as she literally gave up her full time salary I don’t think you could ask for much more. Especially at such a stressful time for her, she might have just felt like she was trying to keep out of the spotlight and made a stance by walking out of her job. Imagine now you having to do the same, I’m sure you’d need a few weeks to gather your thoughts. Let’s not place blame here where it isn’t needed.