Another soldier, Aaron David Robinson, is suspected of bludgeoning Guillen with a hammer at Fort Hood in April, then dismembering her body. When police tried to contact Robinson in July, he killed himself.
Guillen's family has said she was harassed in the Army before being murdered.
"Vanessa told her family that she experienced sexual harassment from a superior, but did not have faith in the system to file a complaint," Rep. Jackie Speier, who introduced the bill with 73 bipartisan cosponsors, said at a press conference Wednesday.
The "I Am Vanessa Guillen Act" would help reform the way sexual harassment is handled in the military.
"This strong, bipartisan bill overhauls the military’s response to missing service members and reports of sexual harassment and sexual assault – specifically, by making sexual harassment a crime within the Uniform Code of Military Justice and moving prosecution decisions of sexual assault and harassment cases out of the chain of command," Pelosi said in a statement Wednesday.
Speir said that in 2018, 120,000 service members indicated they were sexually harassed, but fewer than 1% made a formal complaint. Rep. Sylvia Garcia, D-Texas, said many current and former service members have similar stories that have come out since Guillen's case received national attention.
"Their stories reinforce the troubling reality that too often female service members do not report their sexual trauma because they fear how their chain of command will respond," Garcia said on the House floor last month. "This is not only wrong, but Vanessa's story has galvanized efforts across the country to put an end to a culture that perpetuates sexual assault and harassment in the military."
Guillen's case isn't the only one that has put Fort Hood under the national microscope though. Sgt. Elder Fernandes was found dead last month after transferring units due to alleged sexual abuse.
The U.S. Army Criminal Investigation Command told local news outlet KCEN-TV that after a "thorough legal review," they determined Fernandes' "allegations were unsubstantiated."
More than two dozen other soldiers from Fort Hood have died this year. The string of tragedies prompted Congress to launch an investigation into the base last week.
House Armed Services and House Oversight subcommittees sent letters to the Secretary of the Army, requesting documents to determine if the deaths "may be symptomatic of underlying leadership, discipline and morale deficiencies throughout the chain-of-command."
The Associated Press contributed to this report.