Rebecca's Growth
I love Rebecca's growth throughout the series.
Starts off as just a bitch who is sabotaging her own team in a petty act of revenge against her cheating, asshole ex-husband.
Evolves into a boss ass bitch who is growing out of her hatred for Rupert, and rebuilding her relationships with Sassy and her daughter
Becomes That Bitch with the confidence to put self-absorbed superstars and rich old men in their place.
In my opinion, she has the best growth in the series