Henry, before his death, had secured his queen with an allowance of ₤7,000 per year, befitting her station.
He had further ordered she be given the respect of a Queen of England, as if he were still alive.
Catherine is able to marry her old love, Lord Seymour of Sudeley (as Sir Thomas Seymour has become).
As they marry within six months of the old king's death, they have to obtain the king's permission for the match.
When their union becomes public knowledge, it causes a small scandal.
Catherine becomes pregnant for the first time, by Seymour, at age thirty-five.
This pregnancy is a surprise, as Catherine had not conceived a child during her first three marriages.
During this time, a rivalry had developed between Catherine and the Duchess of Somerset, the wife of her husband's brother, the Duke of Somerset, which became particularly acute over the matter of Catherine's jewels.
The duchess argued that the jewels belonged to the Queen of England, and that Catherine, as queen dowager, was no longer entitled to them.
Instead, she, as the wife of the protector, should be the one to wear them.
She invoked the Act of Succession, which clearly states that Catherine has precedence over all ladies in the realm; in fact, as regards precedence, the Duchess of Somerset came after the Ladies Mary and Elizabeth, and Anne of Cleves, styled the King's Sister.
Eventually, the duchess wins the argument, which leaves her relationship with Catherine permanently damaged; the relationship between the two Seymour brothers also worsens as a result, since Lord Seymour sees the whole dispute as a personal attack by his brother on his social standing.
Catherine's marriage has also come under strain.
Sex during pregnancy is frowned upon during the sixteenth century and Seymour has begun to take an interest in the Lady Elizabeth (Catherine's teenage stepdaughter (the future Queen Elizabeth I), who had been living in their household.
He had reputedly plotted to marry her before marrying Catherine, and it will be reported later that Catherine had discovered the two in an embrace.
On a few occasions before the situation risked getting completely out of hand, Catherine appears not only to have acquiesced in episodes of sexually charged horseplay, but actually to have assisted her husband.
Whatever actually happened, Elizabeth had been sent away in May 1548 to stay with Sir Anthony Denny's household at Cheshunt.
She will never see her beloved stepmother again, although the two correspond.