i'm still reading this thread. But, Elfreida's father owned a pharmacy. Maybe someone convinced her to sneak out some painkillers? Like, say, Hitchcock of the broken leg? But, the painkillers were instead used on Elfreida. This is why she didn't go into shock and die before she could finally be taken to the doctor. Painkillers in 1928 were no joke. I'm pretty sure HEROIN was legal around that time. Maybe not OTC, but possibly available in a pharmacy.
ETA link
http://en.m.wikipedia.org/wiki/Heroin
No, heroin became illegal in 1924. However, surprise, it still is used sometimes except not called heroin. Obviously, things have to be very severe. But, just because it was no longer legal doesn't mean Elfrieda couldn't get some because it was only four years later at that point.