From boverijuancarlospintores.blogspot.com; image made lighter by gogm.
Lady Susannah wears a 1780s-style boffant coiffure with large challah bread-like curls and dress with ruffles decorating her neckline in this Hoppner portrait from around 1785. The dress may have bows en échelle as in earlier decades. Maybe she wears a coat with wide lapels or her dress has a capelet. Her dress may also have sheer sleeves.