Thanks
Yes, I am confident of this marrage
http://www.30jaehrigerkrieg.de/gunn-guin-gwynn-gwin-guon-gunne-guyn-william-wilhelm-freiherr-von/ (about her father, Baron William Gunn, who fought in the Thirty Years War) translated into English, says:
"
In 1639 he was made a baron. On 6.6. In 1640 he married in Ulm Anna Margareta von Freyberg [1609-?], who was fond of the Schwenckfeld sect[168], the daughter of Georg Ludwig von Freyberg, Freiherr von Freyberg-Justingen [1574-1631] and Barbara von Eberstein, Countess von Eberstein-Rixingen [approx. 1572-?]."
and
"His daughter Anna Barbara [1640-1681] married Franz von Weltz Freiherr zu Eberstein [23.7.1635-1674]. In the marriage letter concept[225], Anna Barbara described herself as belonging to the Reformed religion.[226]
Gunn's planned Staufeneck sale was not completed until 1665 by his widow Anna Margareta von Freyberg and his daughter Anna Barbara Freifrau von Weltz zu Eberstein, namely to Ferdinand Freiherrn von Degenfeld,[227] son of Christoph Martin von Degenfeld, who was a friend of Gunn's.[228]"
[225] Hohenlohisches Zentralarchiv Neuenstein: Sf 75 Bü 143.
[226] is just a discussion about the definition of "Reformed Religion".
Also, the Wikipedia article for her daughter, Barbara Franziska of Welz-Wilmersdorf ( https://en.wikipedia.org/wiki/Barbara_Franziska_of_Welz-Wilmersdorf ), says:
"Franziska Barbara of Welz-Wilmersdorf (4 August 1666 – 3 April 1718 in Wilhermsdorf) was baroness of Wilhermsdorf. She was the daughter of Francis of Welz-Eberstein (1635–1674), Count of Welz, Baron of Eberstein, and Anna Barbara de Gun (1640 – c. 1681), daughter of William Gunn (born 1600), Freiherr von Ulm"
(But note that that text makes it sound as if BOTH "Weltz" AND "Ebertsein" are titles, not names.)