I think it's cute. A leather belt instead of the tie sash and some longer necklaces would help moderize it. You could also wear it open with a cool printed tank.
I was thinking about the belt too, maybe replace with a colorful sash or scarf the way smash does it, and possibly the buttons, if you still feel it's not "modern" enough
For winter, a color longsleeve shirt with patterned and/or colored tights, since the color is plain.
I think this is very cute, and could look Sex and the City with the right accessories. Adding a colorful belt or scarf at the waist would look good, and I also think peep toe sandals or pumps.