Margie Reckard, 63, was among the 22 people killed in the Aug. 3 shooting, leaving behind her husband, Antonio Basco.
Perches Funeral Home wrote a Facebook post saying anyone was welcome to attend services there honoring Reckard on Friday, since Basco has no other family nearby.
“Mr. Antonio Basco was Married for 22 (years) to his wife Margie Reckard, He had no other family. He welcomes anyone to attend his Wife's services," the statement said.
"Let's show him & his Wife some El Paso Love #EPSTRONG."
The response has been so good that the funeral has been moved to a larger venue, although it will still take place on Friday.
The outpouring of support impressed U.S. Rep. Veronica Escobar, who is touched by the way residents of the city have rallied around Basco in his time of grief.
"El Paso once again does her thing," she wrote on Twitter. "Because of our beautiful community’s overwhelming response, Ms. Reckard’s services have to be moved to a larger venue. Her husband will receive a flag flown over the U.S. Capitol in her honor."
Reckard’s daughter-in-law, Hilda Nuzzi, who will be making the trip in from out of town, told El Paso NBC affiliate KTSM, “We want to thank the people of El Paso because without them I don’t know what we would have done. Everyone is amazing.”
Basco said his wife was "an angel" to him.
“I mean you didn’t even have to be there to talk to her. You could just look at how she was, how she acted, how she presented herself. She was an awesome lady,” Basco told local KFOX-TV. “You see Margie, more or less, was the brains of the family.”
“I just feel it and when we first met, that feeling came to each one of us, to each other, and we’ve been together ever since. We were gonna live together and die together, that was our plan.”
Accused Walmart gunman Patrick Crusius, 21, has been charged with capital murder and was being held in an El Paso jail without bail. Police said he confessed to the shooting and admitted he was targeting people of Mexican descent.