"The family chose a design with the guidance of a Spring Grove employee who unfortunately made an error in judgment," the cemetery's president told CNN. "The monument does not fit within Spring Grove Cemetery guidelines, was not approved by senior management and cannot remain here."
The tombstones were purchased to commemorate Walker who survived two tours of duty in Iraq only to be killed, allegedly by her boyfriend, when she returned.
The family decided to get two monuments to commemorate her and her twin sister, who is an IT specialist for the Navy.
"Every year, my sister had a SpongeBob birthday party," Walker's twin sister Kara said. "Everything she had was SpongeBob."
Deborah Walker said the situation was devastating because they "were just trying to honor her wishes."
The family is set to meet with officials from the cemetery Tuesday to come up with a solution at the graveyard's expense.
