The word _resident_ at that time implied ownership.
A resident of the parish will have owned property. They own a residence.
Being described simply as _of the parish_ indicates the person lived there but did not own the residence. A spinster, as likely as not, still lived with her parents.
I have a number of relatives who lived in or near Milverton around this time. Some are labelled resident others not. I have tracked down some property ownership records online which seem to confirm this distinction.