The old woman’s clothes are distinctly 1860s, probably around the middle of the decade. Bonnets were still popular among older women. The dresses waistline is a bit higher than the natural waist, which happened as the decade progressed. The woman’s bishop sleeves, in particular, indicate the second half of the decade as these began to replace Pagoda sleeves in about 1865. Her skirt has minimal crinolining but this could maybe also be attributed to the woman’s age. Additionally, the cardstock is distinctly from this decade as well.
Not sure about the middle photo – I’m not much for dating children’s clothes – but the cardstock would indicate 1870s or 1880s.
The third photo is pretty clearly 1870s. The hair, the dress, the headshot pose and the cardstock all the 1870s at their best.
