Changes in gait can be from disorders that would fill this entire website so specifics are needed (foot drop gait, antalgic gait, Trendelenberg gait, circumduction gait, etc…).
Hemangiomas are naturally occurring in the vertebral bodies and are generally not a worry.
Your sister has mild degenerative disc disease at L4-5 and L5-S1. There is minimal compression of the nerves and generally, nerves can take moderate compression before they become symptomatic so it is unlikely that the gait disturbance is from nerve compression.
Does she have severe lower back pain that causes her to demonstrate an abnormal gait? If not, her gait disorder is more likely not originating from the lumbar spine.
Dr. Corenman