Complex sentence: In the first quarter of the 19th century, Grisette also came to refer more specifically to the independent young women, often working as seamstresses or milliner's assistants, who frequented bohemian artistic and cultural venues in Paris.
Split into simpler sentences: In the first quarter of the 19th century, the term Grisette also came to refer more specifically to the independent young women. These, often working as seamstresses or milliner's assistants as well frequented bohemian artistic and cultural venues in Paris.