The actress paired her bejewelled LGD (that's little grey dress) with an oversized blazer and sequin-embellished Mary Janes. Cute!
It's good to see we're not the only ones who are making the most of wearing opaque tights with everything either.
Gemma kept her hair and makeup understated and completed her party outfit with a navy clutch.
See more of the star's spot-on style below: