Broken Strings — Nancy Means Wright

When puppeteer Marion collapses during a performance, her friend Fay promises to carry on. But Fay, a neighbor of Ruth Willmarth, already has her hands full with three demanding foster children. When an autopsy reveals that Marion had swallowed a dose of deadly crushed yew -- and a friend finds her sister dangling from a rod like a marionette, a shocked Fay races after the villains. Mystery by Nancy Means Wright; originally published by Enigma/GMTA Publishing