Foot drop, sometimes called drop foot, is a general term for difficulty lifting the front part of the foot. If you have foot drop, the front of your foot might drag on the ground when you walk. Foot drop isn't a disease. Rather, it is a sign of an underlying neurological, muscular or anatomical problem.
It's possible it occurred when she was in labour, as she stated she was in for like 60 hours (props to you girl) which would've done an absolute number on her nerves.
"The most common cause of foot drop is peroneal nerve injury. This nerve is also called the fibular nerve is a branch of the sciatic nerve. It supplies movement and sensation to the lower leg, foot, and toes. Conditions that affect the nerves and muscles in the body can lead to foot drop."
So yeah, sounds like nerve issues from the force of labour and length of labour.