A girl/woman/female who loses her temper and/or gets enraged at her partner for no apparent reason. She will often, out of nowhere, get incredibly angry at her partner for reasons that defy all forms of human logic and understanding.
"You see that girl. She's a proper Newlands. I saw her the other day explode at her boyfriend and all he did was buy her flowers."
"Sorry man, I can't come out to night. the GF is being a real Newlands"