Certainly, the reunion scene between Dr. Manette and Lucie has a sentimental quality to it; Dickens plays up the emotional side of the scene in Lucie's reaction to seeing her long-lost father:

"With the tears streaming down her face, she put her two hands to her lips, and kissed them to him; then clasped them on her breast, as if she laid his ruined head there" (Book 1, ch. 6).

Lucie's tender reaction to her father's ruined state brings a decidedly sentimental and emotional quality to the scene; when Mr. Lorry is more than a little perturbed at Dr. Manette's struggle to recall his past life, Lucie uses a gentle approach and kindness to help her father understand her connection to him.  She speaks to him softly and gathers him in her arms. Dickens characterizes Manette's reaction to her comfort as being extremely childlike.   Dr. Manette's weakened and confused mental state has resulted in their reunion being bittersweet, but it is Lucie's adept handling of the situation that helps the doctor slowly begin the process of being "recalled to life."

What is your opinion of Dr. Manette meeting Lucie in the attic in A Tale of Two Cities?

While Chapter 6 of Book the First, "The Shoemaker" seems rather contrived and melodramatic.  For instance, when the demented Dr. Manette begins to recognize the golden hair of Lucie as similar to that which he carries in a dingy little packet, Lucie falls upon her knees as his tone of voice softens in remembrance of his wife.  In a Victorian melodramatic line--one that Dickens's audiences would have enjoyed--Lucie utters her maudlin plea, 

"If you touch, in touching my hair, anything that recalls a beloved head that lay in your breast when you were young and free, weep for it, weep for it!...If I bring back the remembrance of a Home long desolate, while your poor heart pined away, weep for it, weep for it!"

This passage is one that critics point to as how Dickens has a very stylized nature that demonstrates the influence the Victorian stage.  As one writes,

Throughout the novel we see Dickens managing his characters like a theater director, emphasizing the dramatic gesture, the physical trait, the coincidence, as though his tremendous energy must inevitably explode into action, whether comic or melodramatic.  Even in his grotesque moments such as Mr. Lorry's questioning of the dead man in his dreams, Dickens converts the morbid into somehting spirited and purposeful.

This melodrama does, however, afford Dickens a scene in which he can depict the horrors of Doctor Mannette's imprisonment, the inner strength of Lucie Mannette as the Victorian heroine, as well as introduction of the motif of "the golden thread."  As such, this chapter is rhetorical in its use of metaphoric language with Lucie's hair as "the golden thread," returning Dr. Manette's memory to him; and with the metaphor of the shoemaker indicating the destruction to the pride and person of the physician. 

Of course, this chapter is pivotal as it initiates the development of the theme of Resurrection.  In addition, it is the catalyst for the action between London and Paris.  Certainly, there is much foreshadowing in this dramatic chapter.