She worked with Dr. Adolf Winkelmann and Dr. Percival Treite,[4] assisting in torture of prisoners[5] and providing postoperative care to the subjects of their experimental operations.

[2] A survivor who worked as a prisoner-nurse testified that Marschall had loaded a group of 50 women with new-born infants onto a cart and did not provide them with food, milk or water.

[2] Another witness testified that "I have seen schwester (nurse) Lisa beating sick women without any reason at all.

"[6] Mil Le Coq, a French trained nurse, reported an incident with Marschall, recounted in The Scourge of the Swastika: A Short History of Nazi War Crimes:[7] She "passed through the hospital courtyard one day on her way to the laboratory and saw five wheelbarrows containing ... five Jewesses - the triangle on their dresses indicated that... Mil Le Coq went to the barrows and touched the bodies to see if whether they were alive and if anything could be done for them.

Nearly 61 when she died, Marschall was the oldest female Nazi war criminal to be executed by the British occupation authorities.