All black seems an odd choice for a midday luncheon in 70 degree weather. I like a little color for a luncheon especially in the warmer weather.
So what kind of food was served?? 
Teasing of course (well, sort of…) but ho-hum on much of what they wore!!! Your outfit sounds perfectly appropriate and YOU. That is most important. 
Well remember it was freezing on Sunday. Weather has been wacky and that woman was actually one who’d come up from the development office in DC - so she may just have listened to the wrong weather report. She had on a scarf that broke up the black. I liked her skirt a lot. I had a leather skirt before second baby that I loved.
As for food… We had tuna tartar on a rice cracker and tomato filled with creme fresh as passed hors d’oeuvres, wine, water or tea offered to drink. Then talk from headmistress. Then buffet style food - sea bass with a miso glaze, a Thai-ish chicken vegetable noodle dish, green beans fried Chinese style, salad, bread and butter. Dessert were tiny litle lemon tarts, spicy ginger bread, choc chip cookies, nut blondie, and brownies. And strawberries. It was all yummy.
Glad you found the perfect outfit!
Sounds like a lovely luncheon.
It’s can be hard dressing this time of year with the weather warm one day and cold the next. Going to DC this weekend (H is running Marine Corp Marathon) and I’m packing lots of layers so I can strip down as day gets warmer. It’s also supposed to rain marathon day but be about 70.
I don’t think it was the perfect outfit, but it was fine. I’m always intimidated by these things. It’s better when I know some of my particular friends will be there, because they are a lot more like me.