Resizing the photo in Family Memories book design software is very easy, just click on the photo, and drag one of the corners of the photo to the size you prefer.

Or if your photo was originally dragged into a template, then you right click on the photo, and left click Fit To Template to resize the photo into the template. Please be aware that if you use the Fit To Template feature, the ratio of your photo might be changed. Just be sure not to distort a photo too much, especially for the portrait photo.