There are numerous incidents and a book has been written about it. I'll Pass for Your Comrade : Women Soldiers in the Civil War by Anita Silvey available at Barnes and NObles and Amazon. It details all the best documented accounts. I have a letter from a Civil War soldier from Saline County who describes how their surgeon discovered when about to amputate a soldier's leg that he was a she. So no telling exactly how many there were. THere was a group of ladies in Tenn who did not even disguise themselves, formed a small company of cavalry and provided support as scouts etc in their area and most were actually captured and help prisoner for a period. I can't remember the county right now.