I agreed that your risk about being sued by any studio who owns the copyrights on your family photos is close to zero percent and even can say is 0%.
You reproduce studio images at home by yourself, probably only God knows your are violating copyright laws.

Almost all studios will not sue you for so small money because they end to pay more in legal processing (I believe no attorneys will take such case too), plus you do have understandable reason.

Unless you are a billionaire, otherwise, copyright laws will not bother you at bit under your circumstance.