Read this: Beyonce and her mother introduced House of Dereon, a contemporary women's fashion line, in 2005. The concept is inspired by three generations of women in their family, the name paying tribute to Beyonce's grandmother, Agnez Dereon, a respected seamstress. According to Tina, the overall style of the line best reflects her and Beyonce's taste and style. Beyonce and her mother founded their family's company Beyond Productions, which provides the licensing and brand management for House of Dereon, and its junior collection, Dereon. House of Dereon pieces were exhibited in Destiny's Child's shows and tours, during their Destiny Fulfilled era. The collection features sportswear, denim offerings with fur, outerwear and accessories that include handbags and footwear, and are available at department and specialty stores across the US and Canada.

House of Dereon became known through Beyonce and which of Beyonce's relatives?
What is the answer? (If it cannot be answered, return "unanswerable")
her mother