I'm sure there are plenty of multi dog households that have had dogs get in fights. It depends on the owner how it is handled. They didn't say on the surrender if this was the first time or what might have triggered it.
The shelter says she is friendly and housebroke (oh and possibly in heat).
She can only be released to a rescue at this point.
UPDATE: The shelter pulled her from the PTS sheet for today, but it doesn't guarantee how long they will hold her, 1 day, 2 days, who knows. If they didn't feel like she was worth a chance they would have not held her past her hold date.