Origins of the Trulls

"English (Gloucestershire and Kent): nickname from Middle English trulle 'trollop; strumpet' or from Middle English trol; trulle 'sorcerer; demon'. English: variant of Trowell. German: nickname for a street entertainer or a cheat from a noun derivative of Middle High German trullen 'to juggle' also 'to cheat'. German: from a short form of the female personal name Gertrud (see Trude)."
Source: Ancestry.com on the name Trull

I have yet to find any clear evidence showing that Trull was originally spelled as Trowell (particularly in the context of this family line), but for what I can find online, it seems to generally be believed that the spelling of the surname changed from Trowell to Trull some time after immigration to North Carolina from England. It appears that the change might have happened sometime in the mid-to-late 1700s, assuming the two names are indeed related; Joseph Trowell was documented living in Chowan Co., NC in 1721, then the next record I can find for a Trowell/Trull in NC is for a Stephen Trull, reported living in Anson Co., NC in 1790 on the census.

"English: habitational name principally from Trowell in Nottinghamshire named in Old English with treow 'tree' + wella 'well; spring; stream'. It may occasionally come from one or more places similarly named including Trowell in Chipstable (Somerset)."
Source: Ancestry.com on the name Trowell

Ancestry attributes both of the above entries on the etymology of Trull and Trowell to Dictionary of American Family Names 2nd edition, 2022. There is also a Trull village in Somserset that may or may not be related to the surname.

Source: Rootsweb.com

"Joseph Trowell & Honer Brian were married the last of October 1683"

"Susanah Trowell daughter of Joseph Trowell & Honer his wife was borne 9th July 1685"

Source: North Carolina Births, Marriages, Deaths, Flesh Marks & Brands 1656-1739 (pages 13 & 26 - free account required to view)