Artist's commentary
A sketch.
Rick (Lydia)
She always wraps her arms in bandages in order to conceal her scars, so she wraps them up properly. However, there are also times when she gets injured badly.
The scars on Rick and Lydia's arms are an easily-recognizable common feature, so regardless of which identity she's portraying at the time, she conceals them as much as possible.
The ones on the edges of her hands and feet, as well as the burn on her back were all received in the same place.
Those scars wouldn't be there if she had abandoned the person she was escorting.
This is to say that really they're "protection scars"