I think the jacket is fine and appropriate, however on me I think it would look better unbuttoned. You might try it that way as well to see if you prefer the look.
Too late for your conference, but if you have a Dress Barn near you that stocks the Jones Studio line in women’s sizes, they have wonderful, work-appropriate suit separates. I’m wearing one of their black suits with a three-button jacket today, one of many pieces I own from that line.
I had a great conference and my suit looked lovely! I will check out the dress barn and anne klein suits as well because I should probably own more than one suit.
Yay! Not everyone is as lucky as I am, with a husband who can pick out excellent clothes for them. 
Other than the funky shoulders (as mentioned above), the jacket would be fine. I’m rather tall and rarely find a suit coat that doesn’t have shirt showing underneath. Either that, or I can have skin showing underneath… and that’s worse.