J.crew has plenty

I’ve found some JJill petite xl or petite xxl Wearever simple shells. Solid colors and short, full length or3/4 sleeve. These work very well well under a jacket — either suit/blazer or more unstructured jacket.

Honestly? You may need to get one custom made or get something you can tailor. Being both plus sized and petite is going to be hard to fit well. Get one that fits your bust and then have a tailor fix the shoulders and sleeves

I’m short and wide and need clothes for work. Really like pretty, dressy, classic blouses without ugly patterns. What are some good online places with a good return policy?