Complex sentence: Everyone supports their wishes except Elizabeth, who is unsure Danny can take care of himself, let alone Carla, who becomes angry, telling her mother she is sick of her dominance and doubt and is also sick of her treating her like an embarrassment.
Split into simpler sentences: Everyone supports their wishes except Elizabeth, who is unsure Danny can take care of himself, let alone Carla. Carla becomes angry, telling her mother she is sick of her dominance and doubt and is also sick of her treating her like an embarrassment.