The questionnaire your secret sister filled out to join the program is full of hints, so you don't need to become an incognito stalker to personalize cards, gifts and notes. Is her favorite color yellow? Next time you're in the home improvement store, pick up several of the complementary paint chip cards in shades of that color to give with a quick note about how the cheery tones reminded you of her. Is her birthday in the fall? A week or two before sending a traditional greeting card, slip a few autumn-colored leaves in an envelope. Add a note about what a lovely season it is for a birthday plus a quote, like Albert Camus' “Autumn is a second spring when every leaf is a flower.” If you've become secret sisters through a women's ministry group, occasionally let her know she's included in your prayers.

The initial excitement of undercover friendship can wane after a few months. Avoid leaving your secret sister out in the cold by making a personal commitment to carry on through the entire year, or whatever time period your group has agreed upon. Enter a “to do” alert on your calendar for each month throughout the year, plus an alert for your secret sister's birthday and any other important dates you want to acknowledge. Buy a box of a dozen pretty cards and write her name on the envelopes as a way to reinforce your dedication. If you move away or are unable to continue offering behind-the-scenes support and secret friendship for some other reason, contact the secret sister program leader and ask for a substitute to take your place.

Little presents like a coffeehouse gift certificate, an inspirational book or a pair of cute socks will give your secret sister a boost, especially when they're unexpected. Kind words, funny stories and uplifting comments are just as important. Some secret sister groups put a limit on the amount of money to be spent. Homemade goodies and inexpensive items with simple wrapping and a handwritten note speak just as loudly as more glamorous gifts. Jot “Wishing you sweetness and warmth” on a notecard and tie it to a packet of hot chocolate mix with a pretty ribbon to make a quick, low-cost pick-me-up for your secret sister in winter. Clip interesting articles from magazines, write down a silly joke you heard and make copies of a beautiful sunrise or flower pictures you took to share. Always sign “From Your Secret Sister,” but take care to leave no clues that could lead to your identification before the designated time.

Your secret sister will find out who's been quietly supporting her, cheering her on and covertly communicating with her at the program's year-end event. These are traditionally scheduled around Mother's Day, the winter holidays or another natural break in the organization's calendar. Make the event extra special for her with one final gift that's meaningful and memorable, such as a fancy picture frame, a festive basket of spa products or a living plant for her garden. Take selfies together and ask a fellow participant to take a more formally posed photo so that you can both have a copy. Let your no-longer-secret sister know when you're available for in-person get-togethers and phone conversations because she's become an important part of your life.