EXCLUSIVE: Queen Elizabeth's Favorite Royal Revealed — And It's Not Her Shamed Son Andrew Windsor

Another royal source said: "What set Sophie apart was that she became one of a very small circle of people around whom the queen could truly let her guard down. In royal life, almost every interaction comes with a degree of formality, obligation or expectation, but that wasn't the case with Sophie. Elizabeth never felt she had to perform a role around her. She could simply enjoy the conversation, the company and the sense of normality that Sophie brought.

"Those who witnessed their relationship often remarked on how comfortable the queen seemed in her presence. There was an ease between them that developed over many years and couldn't be manufactured. Sophie wasn't trying to impress the monarch or gain favor – she was simply herself, and that authenticity resonated deeply with Elizabeth.

"The queen was surrounded by relatives, advisers and courtiers, many of whom she loved and respected, but trust was something she gave sparingly. Sophie earned that trust through consistency. She was dependable when called upon, discreet when dealing with private matters and never someone who created unnecessary complications or distractions.

"As Elizabeth grew older, those qualities became even more valuable. The stability Sophie provided, both personally and professionally, was something the queen came to rely upon. At a time when the Royal Family was navigating periods of significant change and occasional turbulence, Sophie was viewed as a calming and reassuring presence.

"There was a feeling within royal circles that she represented exactly the sort of character the queen admired most – loyal, hardworking, sensible and entirely focused on supporting the institution rather than promoting herself. That is why many people believe she became one of the most trusted and valued members of Elizabeth's inner circle during the latter years of her reign."

Another source stressed Sophie's down-to-earth approach was a major factor in the success of her relationship with Elizabeth.

They said: "One of the things Elizabeth appreciated most about Sophie was that she never appeared overly concerned with the trappings of royal status. The queen admired people who were comfortable in their own skin and who didn't feel the need to surround themselves with unnecessary privilege, and Sophie embodied that approach from the very beginning.

"Sophie struck Elizabeth as being refreshingly grounded. Despite marrying into one of the most famous families in the world, Sophie maintained a practical outlook and avoided the kind of entitlement or grandiosity that can sometimes accompany public life. The queen respected the fact that she preferred a relatively straightforward way of doing things and was not constantly seeking special treatment.

"There was also a genuine warmth and lack of pretension about her that Elizabeth found appealing. Sophie wasn't someone who relied on rank or title to define herself. She was approachable, easy to talk to and capable of putting people at ease, whether they were members of the Royal Family, palace staff or members of the public.

"The queen often valued substance over showmanship, and she saw those qualities in Sophie. She liked the fact that she was sensible, unassuming and largely uninterested in creating a fuss around herself. In an environment where appearances can sometimes become all-consuming, Sophie stood out because she remained remarkably normal.

"Those close to the late monarch often felt that this absence of airs and graces played a significant role in the bond they developed. Elizabeth viewed Sophie as someone who was genuine, dependable and refreshingly down to earth, and that authenticity helped lay the foundations for one of the closest relationships she enjoyed within the Royal Family."

The insider also suggested the late monarch viewed Sophie as something more than a daughter-in-law.

They said: "Over time, many people around the queen came to feel that her relationship with Sophie evolved into something far deeper than the traditional bond between a monarch and a daughter-in-law. There was a warmth, affection and level of emotional closeness that reminded some observers more of a mother-and-daughter relationship than a formal family.

"Elizabeth had always valued strong family ties, and there was a sense that she found in Sophie many of the qualities she admired most. She was loyal, supportive, sensible and consistently present when needed. As the years passed, those qualities helped create a connection that became increasingly personal rather than purely institutional.

"The queen was enormously fond of Sophie and often seemed to take a special interest in her wellbeing and success. She championed her within the family, trusted her judgment and appeared genuinely pleased to have her by her side. That sort of encouragement went beyond what many would expect from a royal relationship.

"Some of those who knew the family well felt that Elizabeth came to view Sophie almost as the daughter she had gained through marriage rather than birth. It wasn't intended to diminish the importance of her relationships with her own children, but it reflected the depth of affection and trust that developed between the two women over decades.

"There was a natural ease and understanding between them that became increasingly apparent in later years. Sophie wasn't simply a valued member of the Royal Family in the queen's eyes – she became one of her closest companions, someone whose presence she enjoyed and whose support she genuinely treasured. That is why many people inside royal circles believed Elizabeth regarded her as something of a surrogate daughter and one of the most cherished figures."