Consider: My sister, Mrs. Joe Gargery, was more than twenty years older than I, and had established a great reputation with herself and the neighbors because she had brought me up 'by hand'.- Charles Dickens Analysis: What does the phrase reputation with herself imply? How does the adjective suit the purpose of the sentence? Would the sentence be strengthened or weakened by changing this phrase?

taking into account that a theme is the central topic a text treats and can be developed through a story, play, poem etc. the following are themes that can be further developed:  

my best friend jeffrey has many unusual interests. (the story could be about each of the unususal interests)

once a man gives his soul over to evil, he can never go back. (this could be a saying or a proverb)

the three sheepdogs lay around the yard all day. (it could be developed detailing how each of these sheepdogs lay around)

a priest's collar has an unusual effect upon people. (it could be developed detailing the different effect upon people)

innocence is a powerful force in a world full of corruption. (it could be developed detailing how is a world full of corruption)

king lear is a play shakespeare wrote later. (it is just a sentence and doesnt give any idea or topic to be discussed in details.

evil often wears the disguise of innocence. (this could be a saying or a proverb)

a few things can be inferred from the excerpt. one thing is the fact the husband and his partner are so comfortable/intimate with each other they don't feel the need to use proper english with one another. another thing is the character has a different relationship with their mother than they do with the husband.