Hilda is a woman in her late thirties or early forties with platinum blonde hair that she wears in a messy bun. The loose strands fall just past her chin.
According to Keeper Yennen, Hilda had lived in Whitestone with her husband for about 15 years before Vox Machina met her. K'rynn, the bounty hunter impersonating Hilda, told Keyleth that Hilda's husband was a sailor who disappeared at sea six months previously. As the bounty hunter had questioned Hilda about her life, there is no reason to believe this wasn't true.
"Taryon, My Wayward Son" (7x13) Edit
Hilda herself actually did rather little in the story. She was held hostage by K'rynn, who asked her questions about her life. K'rynn then disguised herself as Hilda and, under that guise, applied for a baking job at The Slayer's Cake in Whitestone. That conversation led to an invite to Whitestone Castle, where K'rynn kidnapped Taryon and disappeared overnight.
The next morning, when Tary was found to be missing and "Hilda" never turned up for her interview, Vox Machina went to check Hilda's house. They found her there, tied up and hidden in a pile of linens, and she told them what had happened. Vax asked her if she really did bake cream puffs, and somewhat jokingly asked if she wanted a job at the bakery.