However, after it was revealed that Cliff was actually the one responsible for the death of their son, he hanged himself, leaving Penelope widowed.
Throughout the SeriesEdit
Upon being alerted of the drowning of their son, Jason, during a boating accident with daughter Cheryl, Penelope and Cliff joined the local authorities at Sweetwater River. Penelope attempted to calm Cliff down when he became verbally aggressive towards the police as they failed to find his son, despite dragging the river. The following week, Jason's body turned up at the shore of Sweetwater and she and Cliff were forced to stand aside as their son's body was taken away in a body bag.
Penelope, Cliff and their daughter were brought down to the morgue in order to identify Jason's body. As the cloth was pull off his head, Cheryl turned away in horror, as did Penelope, however, Cliff was far less emotional, mutely staring at the corpse of his son.
In spite of all that had happened, Penelope and Cliff attended the annual fall Pep Rally at Riverdale High School. They sat stiffly in the front row of the bleachers as Mayor McCoy dedicated the night's event to the memory of Jason. Shortly after the performance of the River Vixens alongside Josie and the Pussycats, they became concerned as Cheryl ran off the stage in tears.
When Sheriff Keller interrogated Cheryl about the lies she had told regarding her last encounter with her brother, Penelope and Cliff interrupted in a state of anger and abruptly ended the meeting. Cliff demanded to know why his daughter was a suspect in his son's murder case. As they rushed Cheryl out of the office, Penelope wondered why Cheryl didn't contact them, to which Cliff replied that Cheryl was a liar.
Despite the recent tragedy, the couple decided to attend the first annual Taste of Riverdale, in which Penelope had a brief, physical altercation with Alice Cooper. Appalled that Alice would dare print Jason's autopsy results in the Register, Penelope slapped Alice on sight and then became very emotional recalling what had happened to her son. Cliff held her and tried to calm her down, calling her "sweetheart". 
Cliff and Penelope invited Sheriff Keller to Thornhill and informed him of their plan to narrow down the suspects in the murder of their son. They provided him with a list of people they had invited to Jason's memorial service. Cliff explained that the list consisted of people that held grudges against the Blossoms, many of them being from the founding families and there was a very strong possibility that the killer would be in the room. Someone in Riverdale killed Jason, he was sure of it.
That night, the Blossom family were joined by Veronica Lodge for dinner, at Cheryl's invitation. It was an uncomfortable time as both Penelope and Cliff were rather rude to her, as well as their daughter. Penelope did not know why Veronica had been invited and Cliff only spoke of their family's involvement in the town's founding, and of Veronica's incarcerated father. During Jason's memorial, Penelope and Cliff stood holding onto one another, as Cheryl hijacked the service to speak to the guests, which they had forbidden.
After learning of Polly Cooper's escape from the Sisters of Quiet Mercy group home, and Betty Cooper's search for her, the Blossoms orchestrated a search party of their own, however, witch hunt would appear to be the more accurate term. With the news of Polly's recent escape moving throughout town, Cliff wondered if it was possible that Polly had escaped before, maybe on the day that Jason was murdered. During the press conference held by Alice Cooper, they learned that Polly was pregnant with Jason's child, their grandchild.
Through Cheryl, Cliff and Penelope arranged a meeting with Betty at Pop's Chock'lit Shoppe hoping to further discuss the plans for Polly and the baby. Cliff and Penelope were relieved to learn that they were safe. Penelope told Betty they wanted to offer emotional support and Cliff assured Betty that money would never be a problem for them. They tried to get Betty to reveal Polly's location but she refused. Penelope reminded her that she and Polly were members of the Blossom family now, and they'd be ferociously protected, as long as they all trusted each other.
Back at Thornhill, Penelope asked Cheryl if she had ever seen Polly take drugs, which Cheryl wasn't sure of, Penelope explained that she wouldn't want an unfit mother to raise their grandchild. They set a meeting with Polly at Pop's but before they arrived Cheryl told Polly to leave and explained that they were not interested in Polly, she was not safe, that all they wanted was the baby.
After attending Polly Cooper's Baby Shower, Penelope apologized for attempting have Polly declared an unfit mother and told her that she would always be welcome in their home and Polly ultimately decided to go and live with them at Thornhill. As Cliff and Penelope led Polly inside the house, they shared a very pleased look with one another.