Question: How old was Rose Hartwick Thorpe when she wrote the poem she would be largely remembered for writing? 
Sentence (from "Rose Hartwick Thorpe"): Rose Hartwick Thorpe (July 18, 1850 – July 19, 1939) was an American poet and writer, remembered largely for the narrative poem, "Curfew Must Not Ring Tonight" (1867), which gained national popularity.
Relevant evidence: Yes