Welcome to Rootschat. It's lovely to have family photos, especially when they are named, but you'll need to start and slowly work your way back through records to find more family details. We can perhaps help find information or suggest where to look if you give us more details.
You'll hopefully know your mother's name and birthdate and perhaps the names of her parents? The most recent Scottish census available is 1901 so if you get that far back there's a good chance of getting much further back through census records.
Scotland's People website is the place to search for births, deaths and marriages- their website will tell you what details are on Scottish certificates and how to buy credits to view the certificates.
There are lots of helpful people on the various Scottish boards and since your roots seem to be Caithness I'm going to move your post to that board to see if anyone can help.