The first photo shows nineteen girls and young women and four boys, ranging in age from about four to perhaps their mid- to late teens.
The second shows forty-four boys sitting, kneeling or standing, with a similar range of ages, and a young man, perhaps aged about thirty, seated at the far right.
The third photograph shows 28 adults (including 21 women and seven men) and twelve children.
Several people appear in more than one photograph. None have yet been clearly identified as a member of the Hewitt family, although there are several possibilities. All are wearing bonnets, bowlers, straw boaters, caps or other hats. The card mount has no printing or inscriptions on either the front or reverse, and therefore provides no clues as to who the subjects are or where the portraits were taken. It seems likely to me that the outing consists of a group of families, possibly related, but not necessarily so, who encountered a travelling or itinerant photographer while on a visit to some local historic building or ruin. If the stone walls can be identified as being from a particular location, then this will help in understanding more about the nature the outing.
It also seems reasonable to assume that at least some are members of the Hewitt family. From the clothing worn by the adult women in the party, I believe that photographs were probably taken in the early to mid-1880s, perhaps between 1881 and 1886. At this time, the Hewitts were living in Derby, having moved there from Alfreton in around 1866. From an examination and analysis of the other photographs in this album, it minght be possible to identify members of the groups shown in these three CDVs, using higher resolution scans of the original.