OP is BU for not showing the dress before disappearing, but some of these comments
"60yr old shouldn't wear mini skirts, certain styles are only for certain ages"...fuck that. What a depressing way to live your lives, and what a shit example to set DC (especially DDs).
A lot of fashion is cyclical, I think a lot of the (currently very popular with younger people) 90s stuff was 60s inspired. I love bell sleeves and A lines, especially combined in a short dress. Something like that will always be style to me - as opposed to fashion.
I am late middle aged and have a shaved head with Mohican, and my young adult DD is currently wearing my Ramones T-shirt. We share docs, shoes, coats etc (mostly mine originally!) and have just agreed we need to buy another particular hat as we both want to wear it
Am I dressing for the wrong age group, or is she? No doubt people will say I am, but fuck it, I still fit in my clothes even if I don't fit in with my peers 
My hair falling out was awful, but shaving it and coaxing what little remains (it was like growing a tiny seedling ) into a style I love, has been a good thing eventually. Buy the dress (but as PP have said, don't machine wash it!) and wear it every single day if you like! I genuinely believe, apart from specific occasions where you should conform to social norms/dress codes eg job interviews and funerals, you can never be overdressed. There's just no such concept in my head. If something is gorgeous and you love it, wear it whenever and wherever you want. If it makes us feel happy, how can it be a bad thing? I will not live what's left of my life choosing my own clothes based on other peoples' opinions, and really want my DCs to have the confidence to feel the same, especially DDs. It would be great if women supported each other to do this, instead of judging each other.