ETA: I must have been ruminating in my sleep because I woke up and put this together. It's based on all your awesome input and ideas, and I will be totally at ease in it. (except for worried about sweating. Silk can feel like a plastic bag sometimes!)

Pics 17-18 - jacket can come off - yay! carrying a pewter tote, like Vix recommended.
Pic 19 - do I dare use my new reading glasses? I don't want my cheaters to shout "old, clueless lady here"

Interviewing tomorrow, and I'm so clueless. I haven't done this formally since maybe the late 80s!! (I think I just fall into my jobs)

I researched old YLF threads for advice, but my quandary is that I don't even know how they dress at this place and I'm not sure how 'professional' this position is - it's only part time, and it could be one step above schlepping mail around the company, but I don't care -- the more I research this (non-profit, financial) organization, the more I WANT TO WORK THERE. ( Plus, we'd really like to get an employer to pay for healthcare instead of us :-\ )

So, I'd love to hear your take on interviewing today, which (if any) outfit looks best to you, and especially if you explain why. I'm all ears

On to the choices (sorry so pic heavy. I must learn an easy way to do collages):
1-4 go together - just various shoes and purses (do you even carry a purse to an interview?)
5-6 - a halter sweater underneath, so the jacket cannot come off!
7-9 are three different dress/jacket combos
10-12 sleeveless dress underneath - can jacket be removed?
13-16 skirt combo with top tucked and untucked, and shoe choices.

It is supposed to be 90F here tomorrow!

Are slingbacks bad to wear for interviews? What about wedges?

I went looking for interview wear, but instead found two cute pair of pointy toe, low heels - hopefully for future work wear

Thank you oh, so much for your help! YLF women are the source of mucho wisdom!!