Great, thanks for the extra information, Jim, that explains so much. 1960s frames and 1980s re-matting both make the artwork look a whole lot younger than it really is. Having said that, portraits in pastel were not a very common thing in America until the 1890s or later and so my guess is these were done quite a while after the daguerreotypes were made which we can date from the hairstyles and clothes to the 1860s or 1870s -with center part and hair pulled back into buns and or braids.
You don't say when Harriet & Caroline were born, but if you know, you'll be able to see if that tallies. If they were brought by their parents from England, chances were they were still in their late teens or early twenties at the time.
These are very well executed portraits. I can plainly see the terrible divot in Harriet's forehead where she was kicked. .
My sister was also kicked by a horse in the face when she was a toddler. She was only two years old and it's remarkable she wasn't killed outright. The hoof crushed her cheek bone but miraculously missed her nose, eye and ear. Even after years of plastic surgery, the shadow of the horseshoe is still plain to be seen.
Valuing family portraits is not an easy thing to do, because the portraits are of most interest only to a very small group of people, namely the family. But one has nonetheless to put a dollar value them on the basis of what they would fetch on the open market, absent of any emotional or ancestral ties. As such, the owners of said portraits are usually disappointed with the amounts. (So please don't shoot the messenger!)
That's because very few of them were done by society painters or by "easel artists" as they were called, and thus signed and listed. They were done by countless nameless professional artists in the same manner as professional portrait photographers operate nowadays.
The premium or credit given to the actual individual professional painter of these, is about the same as the premium or credit to the photographer who took that daguerreotype, in other words none at all.
They do, however, have a value as period pieces and to those interested in social history and collectors interested in preserving or recreating historic interiors.
Truth be told, the Victorian cameo brooches pinned to their lace collars would be worth about the same, if not a little more, than the entire painting. I do hope you still have at least Caroline's in the family jewelry box!
Looking at comparables, this similarly well-executed & sized and date, unsigned, pastel portrait of a Boston lady, but in a more desirable and period frame, sold at auction for $800.
I would give each of yours an auction estimate in the range of $700 - $1000.
Full retail/replacement/insurance value: $2000 for each and $4500 for the pair, on the basis that a pair is always worth a little more than the sum of the values if sold singly.
Hope this helps.