Is it appropriate at Thanksgiving to unveil my secret sister and dad’s affair?

Dear Prudence,

My father had an affair many years ago, and I found out about it. The affair had resulted in the birth of my half sister, Annie. Dad has successfully kept Annie a secret for 25 years. She’s now a young married mother, and we are somewhat close friends. While my mother knows of Annie, she does not know she’s my sister. My parents divorced when Annie was 5 for unrelated reasons, but my parents still get along quite well. I host Thanksgiving each year. Mom and Dad are coming.

Annie just told me that she would like to be invited to Thanksgiving. While I have explained the situation to her, Annie says she’s tired of being kept a secret. I’m worried of not only causing discomfort for my dad, but also humiliation for my mom if Annie decides to let the cat out of the bag. I have tried to tell Annie that we could have a get-together some other time, but she insists. What should I do?

— Holiday Host

Dear Host,

You surely want to avoid a pumpkin-pie-throwing contest on Thanksgiving. There’s something so despicable about trying to keep the existence of certain people a secret for the sake of other people. How hurtful this situation is to Annie and how humiliating it is for your mother. You’ve got little time to address this so that Thanksgiving is not a debacle. Tell your mother the truth, and set up a meeting for you, her and Annie. Yes, it’s going to be a shock, but she’s been divorced from your father a long time and it’s well past the point that she should know you have a half sister.

— Prudie

Dear Prudence,

My husband’s sister Susan was recently diagnosed with early-stage cervical cancer. Her care plan calls for six weeks of chemotherapy and radiation treatments. There is a facility less than 30 minutes from her home where she can get this treatment. Another one, slightly better, is 15 minutes from my home. Susan lives three hours away and has asked if she can stay at our house for her six-week treatment, with me providing transportation to her appointments. She and her husband are in dire financial straits. Neither is working; the husband is on an endless money-for-nothing quest. Susan is one of the kindest people on earth. However, lodging, caring for and transporting Susan for six weeks would destroy my family’s tightly structured budget.

My husband and I have two school-aged children, and I worry how this would affect them. I’m a stay-at-home mom, but my days are filled with typical mom-errands. Am I being horrid and selfish if I encourage her to seek treatment at the facility closer to her home?

— I Guess It’s All About Me

Dear Guess,

It certainly sounds as if Susan’s realizing her life’s helpmeet is no help and not meeting her needs. But unless her husband is an irredeemable bum, now is the time for her to insist he put aside his get-poor-quick schemes and step up and attend to her during her illness. After all, an out-of-work husband is in an ideal situation to take her to treatments and bring her chicken soup. You don’t say whether Susan’s primary motivation is superior treatment or moral support, but since you say the facility near you is only slightly better, and she is not having, say, delicate brain surgery, I assume her request is less medical than personal.

If you were to have Susan stay with you, it would be a generous thing to do, and I can’t imagine that one extra mouth to feed and trips to the hospital would destroy your family’s budget. But Susan’s request for six weeks of nursing is a serious imposition, and you’re not horrid for not wanting to shoulder it. It’s time for Susan’s extended family to come together to see how they can support her. Maybe everyone can chip in and give this pair money to pay for gas and some meal deliveries. Possibly you, your husband, and other family members could take turns spending a weekend each with Susan to help with her care and lift her spirits. No matter where she has her treatments, she can find services for getting her there and back and other kinds of support at the American Cancer Society. And you should feel fine about trying to find that sweet spot between selfish and saintly.

— Prudie

Please send your questions for publication to prudence@slate.com. Questions may be edited.