Neither Lady Salisbury, nor Lady Exeter were tried. Lady Salisbury was moved to the Tower, and summarily executed in 1541, with no trial or formal charge ever having been made against her.
Lady Exeter was released in 1539, and given a pension, although the Exeter estates remained confiscated.
The two boys remained in the Tower. Henry Pole, Montague's son, disappeared and Edward Courtenay, Exeter's son, remained imprisoned until 1553.
The Tudor Times also presents some theories about why Henry VIII and Thomas Cromwell, on pretty flimsy evidence, accused these families of treason and acted against them:
Others historians are in agreement with the contemporary European assessment about dynastic fears. Both France and the Empire believed that Henry's concerns were dynastic, and that he wished to annihilate the remaining members of the House of York. Exeter was his first cousin and grandson of Edward IV, and Montague was Edward IV's great-nephew. M L Bush and Dr David Starkey disagree with this assessment, pointing to the favour shown by Henry to his relatives.
Far more worrying than a claim by Montague or Exeter was the idea that his "illegitimate" daughter, Mary, might marry Reginald Pole (who, despite being a Cardinal was not actually a priest) and be placed on the throne by a popular uprising. Mary's reinstatement in the succession had been a demand of the Pilgrimage of Grace, and the Poles and Exeters had been strong supporters of Mary and her mother, Katharine of Aragon. Henry would have been determined to protect his baby son, Edward, at all costs.
Another theory is that the Poles were being punished for Reginald Pole's activities abroad and certainly, if Reginald had not written De Unitate and not attempted to provoke an invasion, then Geoffrey would not have been committing treason by corresponding with him or trying to join him. However, this does not seem to account entirely for the charges against Exeter, Nevill and Carew.
Here's a link to the timeline of events.
however, and he ended up in exile.
Margaret Pole was held in the Tower until May 27, 1541 when she was brutally beheaded (without charge, trial, or conviction). That must be one of the low points of Thomas Cromwell's career as Henry VIII's henchman. Henry Pole, junior we could call him, Montagu's son, was held in the Tower until his death in late 1542--Alison Weir believes of starvation.
Image Credit: Henry Courtenay, KG, shown 2nd from left wearing a mantle displaying the arms of Courtenay, with in the 1st quarter the Royal arms of England within a bordure counter-changed, detail from procession of Garter Knights in the Black Book of the Garter, c.1535, Royal Collection, Windsor.
Image Credit: Portrait of Edward Courtenay, 1st Earl of Devon (1526 - 1556). In background a ruined castle, possibly Tiverton Castle, seat of the Earls of Devon