They construct a new Save Daddy Plan, and catch the criminal that was stealing Iantha's computer because he thought she was stealing his research, which was not true.
Tommy then reveals his feelings for her, and they start dating.
Rosalind leads the MOPS and is anxious without, to the point where she squeezes Batty very hard in worry.
She introduces a list of rules to the three younger sisters.
She is dismayed and embarrassed when she realizes that Cagney only sees her as a little kid, and hopes that she didn't come across as too eager to spend time with him, despite her constantly making him brownies.
She is kind to Jeffrey, and while she doesn't develop as close of a relationship with him as Skye and Jane, she is always there for him and serves as his level-headed adviser throughout the story, especially at the end when he plans to run away from home.
Batty is excited for her homecoming and has a countdown to it.
Rosalind comes home early with a junior named Oliver, who the rest of the family and Nick don't care for.
She, according to Batty, still cries in her sleep sometimes.She most often takes the postion of OAP (Oldest Available Penderwick). Rosalind was really sad about her mom dying and promised her mom to take care of her younger siblings, Skye, Jane, and Batty.After finally arriving at Arundel Gardens, Rosalind meets and immediately becomes smitten with a handsome young man named Cagney, Mrs. Rosalind is thrown into a whirlpool of emotions over whether or not it is appropriate to have such a crush on Cagney at the tender age of 12, especially while acting like a maternal figure to her three younger sisters. The book portrays her as the prettiest of her sisters, and it seems like she is the one most affected by her mother's death.Rosalind eventually breaks up with Oliver, to everybody's relief.Rosalind is caring and responsible, and as the eldest sibling has done a great deal looking after her family since her mother died four years prior.
She is shooed off at the end of the MOPS, and leaves the next day, to Skye's despair.