Write a letter of congratulations on engagement.
Dear Stella,
While we are not altogether surprised, we are both delighted to hear the good news of your engagement. Ted's family and ours are very close, as you know, and we have always been especially devoted to him. He is one of the finest-and now luckiest-of young men, and we send you both every good wish for all possible happiness.
Affectionately,
Nancy Jackson