Excellent question. Terentia was of vital importance to Cicero's career. She was the daughter of a prominent plebeian nobilis family (like Cicero, Crassus, Pompey, Cassius, Cato, Brutus, Antony, Lepidus, Octavian, Hortensius, Lucullus, etc. she was not a patrician. The patrician order is not synonymous with the senatorial class or the nobiles and by Cicero's lifetime only 14 patrician families still existed, it's actually pretty hard to find patricians of any note during the period) and her financial and political support were invaluable tools to Cicero. Cicero, though of an equestrian family, was not spectacularly wealthy, but Terentia was, and possessed a rather sharp mind. Plutarch tells us, referring to some passage of Cicero's that has not survived, that Cicero himself said that Terentia was strong-willed and quick-witted and that she was more interested in involving herself in his political affairs than in dealing with domestic issues. Terentia was of crucial help during several points in Cicero's career. When Cicero was unsure what to do about the Catilinarians Terentia brought him news from the Vestals that the sacrificial fire had shot up all of a sudden, and she persuaded him that this was a good omen and that he should execute the Catilinarians immediately. In 61 Terentia's intervention was vital in the severity with which Cicero attacked Clodius, with whom he had been on fairly good terms before, and was particularly important in Cicero's dealings with Clodia, whom she despised. Terentia, like Cicero, suffered for her opposition to Clodius. Late in 59, when it seemed that Cicero might accept Caesar's invitation as legate in Gaul, Clodius tried to reconcile with Cicero by placing the blame on Terentia, according to Plutarch--this gives some indication of how much influence she was thought to have in Cicero's affairs. When Cicero rejected Caesar's invitation and Caesar unleashed Clodius on him to silence him once and for all, Terentia suffered from her opposition to Clodius. We don't know all of the details, but Terentia had to take sanctuary in the temple of Vesta (her half sister was a Vestal) and Cicero mentions in a letter that Terentia was forced to appear (Cicero describes it as though she were dragged along as a captive, but this must be rhetoric) at the tabula Valeria (exactly what that was is debated) for some sort of financial matter. It seems that either Terentia was forced to make a statement on her husband's property (which she may have been trying to hide), or perhaps her own property, or perhaps she was trying to borrow money--in any case this seems to have been related to the confiscation of Cicero's property, as Terentia owned property in her own name that was not confiscated and that Cicero relied on during the 50s, he mentions her property several times in his letters and is frequently asking for loans from her. Terentia during Cicero's exile was sui iuris, and as such maintained herself openly as a political power in her own right--her lobbying for Cicero's return gained great support for the motion and was of not insignificant importance in Pompey's self-serving decision to override the exile. And she was of no small amount of indirect political influence, since she arranged for a political marriage between Tullia and Dolabella while Cicero was away in 50 as governor of Cilicia.

Terentia's marriage with Cicero fell apart probably due to financial reasons. Cicero claimed that during the civil war she had failed to join him in Pompey's camp and that she spurned him when he returned to Italy. It's a bit hard to believe that this was solely Terentia's fault, as despite their somewhat rocky relationship in the later years of their marriage Terentia had always been a very dutiful wife to Cicero. Terentia claimed that he had fallen shamelessly in love with his second wife Publilia (who was something like thirteen at the time, which seems to have attracted rather negative remarks, according to Quintilian). Plutarch says that Tiro claimed that the divorce was in order to allow Cicero to pay off his debts. Plutarch, using Tiro as his source, says that Cicero, who was in horrible debt by 46, had been made Publilia's legal guardian, and hoped to use her vast wealth to pay off his debts--by marrying her not only did he have guardianship over this property, but could now legally use it as his own. Certainly Terentia's money was vital in maintaining Cicero after this return from exile, and in the last few years of their marriage Cicero often complains to Atticus that Terentia was behaving miserly and not giving him the money he needed. So that gives us some indication of her financial importance

Even after their divorce Terentia seems to have kept a political mind. According to Jerome she married Sallust (the historian and Caesarian, who as tribune in 52 had opposed Cicero and to whom Quintilian wrongly attributed the Invectiva in Ciceronem) and then later married Valerius Messalla, who fought under Cassius at Philippi but later became an important supporter of Octavian, fighting against Sextus Pompey and was consul with Octavian at Actium--it was Messalla who proposed that Augustus be given the title pater patriae (first used unofficially, of Cicero, in 63, after the Catilinarians were executed) in 2, B.C. So Terentia had good political sense and was able to follow her nose, perhaps better than Cicero himself, whose errors in whom he trusted and whom he attacked between 44 and 43 cost him his life. Terentia's death at age 103 is preserved by two sources, Pliny the Elder and Valerius Maximus--the date of her death is not known but it can't have been long before Valerius Maximus' birth, if the age of her death transmitted by the tradition is accurate