“We’ll never know”
Yes, we do. How? Because if she had renounced her US citizenship, Ted would not be a US citizen. Since Ted has a passport, it means there is no paperwork on file renouncing her US citizenship.
“Gather the renunciation fee. Due to a large number of Americans renouncing citizenship, the State Department has increased the renunciation fee in recent years. It now stands at $2,350. Make sure you have this fee ready for when you go to renounce your citizenship...
...Appear before a diplomatic officer. You have to appear in person to renounce your citizenship; it cannot be done through the mail or a mediator. Once you’re at the embassy, you’ll have to verbally state your intention to renounce US citizenship in front of a diplomatic officer...
...Sign the oath of renunciation. After you meet with the diplomatic officer, he will present you with an oath renouncing your citizenship. Read this document carefully and consider your decision before signing it. After you sign the document, there is no going back....”
http://www.wikihow.com/Renounce-American-Citizenship
A person wishing to renounce his or her U.S. citizenship must voluntarily and with intent to relinquish U.S. citizenship:
appear in person before a U.S. consular or diplomatic officer,
in a foreign country (normally at a U.S. Embassy or Consulate); and
sign an oath of renunciation
Renunciations that do not meet the conditions described above have no legal effect. Because of the provisions of Section 349(a)(5), U.S. citizens cannot effectively renounce their citizenship by mail, through an agent, or while in the United States. In fact, U.S. courts have held certain attempts to renounce U.S. citizenship to be ineffective on a variety of grounds, as discussed below.
...Finally, those contemplating a renunciation of U.S. citizenship should understand that the act is irrevocable, except as provided in section 351 of the INA (8 U.S.C. 1483), and cannot be canceled or set aside absent successful administrative or judicial appeal...”
Therefor, it is safe to say she did not renounce her US citizenship.