I've seen Jewel post that she was wearing this designer, Alice + Olivia, a couple times. Turns out she's got a deal with them for their I'm A Boss campaign!
Some more native promotional work:
Lauren Gott did the make-up for this campaign. She's been working with Jewel since 2009 and is responsible for some of Jewel's prettiest looks, including this campaign.
If you're on Instagram, this account is worth a follow:
https://www.instagram.com/laurengottmakeup/ along with Jill Buck on hair
https://www.instagram.com/jill901/