Me neither TerriBull. They have always been bracelets or bangles.
I see that the OED defines:
slave bracelet n. originally U.S. formerly, a slave's identity bracelet worn on the wrist or ankle; now, a bangle of metal, glass, bone, etc., worn for ornament, frequently above the elbow.
Interestingly, the first documented written source is from Webster's Dictionary in 1934, long after abolition.
Notably, Raymond Chandler used the term in his 1940 novel
Farewell, my Lovely An emerald..that..managed to look as phony as a dime-store slave bracelet.
So while I'd like to resist the excuse that it's a term passed down from parent to child similar to the predominantly post-war terms which abounded for shops and restaurants run by people of non-white ethnicities, I wonder who brought it into British use, whether the OP can recall where she learned the phrase from.
Old sayings with a theme 2 ( continuing *nanna8*'s thread)
Last weekend, in Rutland, the first statue in Britain of the late Elizabeth II was unveiled.