library(dplyr)
library(stringr)

str <- "THE QUEEN'S HAND"
nchar(str) < 2 || ! str_detect(str, "[[:lower:]]")

str <- "##45$&%&3#"
nchar(str) < 2 || ! str_detect(str, "[[:lower:]]")

str <- "a"
nchar(str) < 2 || ! str_detect(str, "[[:lower:]]")

str <- "THE QUEEN's HAND"
nchar(str) < 2 || ! str_detect(str, "[[:lower:]]")