You are indeed fortunate to take Silverseas. The ships are stunning and the staff is superb. I've never been as pampered in my life!!
In August you may find a few families but the passengers are quite a bit older. But the same was true when I sailed and yet I met some fascinating people and had a great time. Because the ships are small, you will bond quickly with others.
Congratulations and have a fabulous honeymoon.