The top right photo would be from the later 1880s or possibly the very early 1890s. I’ve read that black card mounts were most popular from about 1877 to 1887. Also, the woman’s dress would be from about this time frame. The tight buttoned line bodice with the severe and slightly high waist was popular in the 1880s. The appear to show a slight lift at the shoulders. This popped up around 1890 (give or take a couple years, I’m not sure of the exact debut) and started a fad of even larger sleeves over the rest of the decade.
I think the bottom photo was probably taken a little later. It strikes me as being more solidly 1890s based on the woman’s dress and, again, the oversized sleeves. The collar also strikes me as being from closer to 1900 than 1880. The man’s suit also would not be out of place for this time period
The family portrait is a bit trickier to me as neither men’s nor children’s clothes changed as frequently as women’s clothes and the older woman’s dress is largely obscured. My best guess, however, is that this is early 1900s from what I can see. Also, the mount seems slightly more modern and unusual than your typical 19th century CDV/cabinet card. That’s just a guess though.