Lady Isabel Rainbird (née Millyzant; 1490 – ????) was the 14th great-grandmother of Cometan, classified as one of Cometan’s distant paternal ancestors in the Stringfellow family line. Born in Walsham-le-Willows, Suffolk, Lady Isabel is known to have been the wife of Thomas Rainbird (1485 – 1539) and to have given birth to at least one son, also named Thomas, in 1516. The details surrounding Lady Isabel’s death remain unknown, although she is known to have died in her hometown of Walsham-le-Willows.
In Cometanic ancestry, Isabel is categorised as part of the 16th generation retrograde, classifying her as a distant ancestor of Cometan.