Hypothetically, my daughter is a defense attorney. My son is dating a woman who, while driving under the influence, kills my cousin’s 16-year-old daughter and her 2-year-old child. My son asks his sister to defend his girlfriend—would that be legally allowed? For context, my cousin’s father is my mother’s brother.

She sounds like a real piece of shit who doesn’t deserve a defense, but that’s just me talking.
Terrible accidemts can happen without malice
Driving drunk was just an accident?
If addiction is a disease