Is it considered acceptable for a woman to wear a black blazer with pinstriped pants, instead of a suit?

I bought the jacket and pants separately. The jacket is all black, the pants are black with white pinstripes. The fabric is nearly identical, but if you look closely it’s clear that this is a jacket-pants combo, not a suit. I work for a non-profit, but have some corporate meetings coming up for work, including one at the New York Stock Exchange. I’m not familiar with corporate dress code and not sure about what will raise eyebrows.

If you think I need to get a different outfit, can I just go back to Banana Republic (where I bought the jacket a year ago) and ask them to match it with black pants? Or do I need to buy a “real” suit?

I’d particularly like to hear from people who work in the corporate world.