Hélène de Montgeroult’s Études are a groundbreaking collection of 114 piano studies composed between 1788 and 1812, bridging the Classical and Romantic eras. They blend technical exercises with high musical expression, foreshadowing composers like Chopin and Mendelssohn.
There is an excellent article by Dr Helen Thomas:
Illuminate Women’s Music: Hélène de Montgeroult (Dr Helen Thomas)
The Listening Project Blog 