There are two different authors here who specialised in needlework:
#1 Mary Thomas 1889- was the English author of Mary Thomas's Book of Knitting Patterns, while #2 Mary Thomas 1934- is the American author of Crocheted Snowflakes.
The #3 author of Apostle of the Valley is Sister Mary Thomas.
#4 Mary Thomas 1906- is the author of In the Shadow of the Rising Sun.
Combination issues