David Perry, a family spokesman, said her family were "stunned" and were enduring a "nightmare".
The hospital and sheriff's department conducted a search of the premises and Ms Spalding's friends and relatives spent days scouring the streets of the California city with flyers.
They said they were "under the assumption San Francisco General had been searched."
Mr Perry said: "Lynne Spalding died alone, in the stairwell, at one of the finest medical institutions in this country.
"I hear that the San Francisco Sheriff's Department initiated a search. Well, evidently it wasn't a very good one. I think there are a lot of questions to be asked."
More top news
'There's still hope - albeit only a teeny, tiny glimmer of it'
An entire North Yorkshire village which was put on the market a year ago for £20 million has been sold for an 'undisclosed' fee.
Middlesbrough 1 Sunderland 0