Unlikely to be the same woman since the first picture dates to the mid 1860s (more specifically from 1863-1867);
Circled in red is a design feature called a 'mancheron' - a high sleeve cap. A style which started in the mid 1840s and gradually fazed out by the mid 1860s.
On the right you can see a very similar extant bodice (a MET museum deaccession) which has been dated to 1865. The trimming on the cuff, mid torso waistband, front button closure, mancheron sleeve cap and crescent sleeve shape are all very similar.
The young boy is also wearing 'mule slippers' - which were an extremely popular part of casual menswear in the early 1860s. The shoes in comparison are an extant example from the early 1860s (the owner took the liberty of modelling them for us). You can see the 'v' shaped vamp and square toe cap are very similar, and I suspect that the pair the boy is wearing would have been decorated with some kind crewel-embroidery (as was fashionable at the time).
Last but not least the hairstyle;
The early 1860s favoured a severe middle parting, with straight well ironed hair which was pulled tightly across the scalp - which was then 'managed' into either a low (emphasis on that) simple bun or (for special occasions) a plait. The fashion plate in comparison is an 1862 hair tutorial from Harpers Bazaar. The later 1860s style began to add more volume to the back of the hair and overall became less 'severe' in appearance.
I would probably predict the woman in the photo to be around 20 years old - putting her birth date c. 1840s. She would have been 50/60 in the early Edwardian period/late 1890s - whether or not the woman in the second picture looks mid 50s is up to you... I'd say not, but saying that, there is an undeniable resemblance (so I could be wrong).
The woman in the second pic is wearing a calico dress. These are often thought of as 'worker' dresses and don't necessarily show off the latest Parisian fashions

The print is very 1890s. I'm not a print expert (no surprises there), so I can't give you an exact date on the fabric. What I can tell you is that the picture definitely wouldn't be the early 1890s - it would be the mid or late 1890s; and that's all down to the hairstyle.
sleeves, print, fit of the dress and neckline - all of it is very practical in design. I believe that the woman in the photos dress may also have a front closure which has been cleverly hidden by a well placed ribbon!
Lastly - the hairstyle (and the reason why I say late 1890s - if
not the early Edwardian period - were talking about a very narrow period between 1900-1903 here).
^ Just to prove my point I made a
very scruffy hair timeline from photos with the precise dates.
As you can see the dress and hairstyle point to the late 1890s - and I could even stretch the date to the early Edwardian period; going by how voluminous her hairstyle, it really resembles a Gibson do (the purpose of the Gibson hair was to not only 'look' good but distribute the weight of the growing Edwardian hat - and trust me - I own a massive antique 1912 picture hat and without such a bouffant the brim of the hat really 'digs' into the forehead... not comfortable).
Hope this helps.
EDIT: In fact - on second thoughts, I think the resemblance is too similar for it not to be the same person! I believe it is the same woman