Clue: The ladY pulled up about 500 thorns (4)
Answer: EDHS
Explanation: Definition: thorns
 D in SHE< – Eth (or edh) and Thorn are letters used in modern Icelandic for voiced and unvoiced "th". According to Chambers, eth was "used without distinction from thorn" in Old English, hence the definition, which surprised me until I looked the word up