Having a first baby is often both a joyful and quite stressful time for the pregnant mother, who may feel overwhelmed at the task of ensuring she and her baby survive the pregnancy and delivery. It sounds as if your sister-in-law is quite scared and may believe the actions she is taking are the most helpful for her and her unborn baby.

If you’ve had a baby yourself, you might reassuringly share your experience of being pregnant with her, particularly by recounting any times that you were sick and got better. You can help her by acknowledging any similar worries you had and encourage her to talk with you about her own fears. Be careful not to judge her feelings or decisions, and try to help her to see herself as strong and healthy enough to fight off whatever comes her way and keep her baby safe. You might suggest that she talk about her worries with her medical practitioner, who might in turn be able to recommend a mental health professional if it seems indicated.

While this situation is causing you concern, ultimately you will have to respect your sister-in-law’s wishes. Take heart that a pregnancy lasts only nine months, and hopefully she will return to her usual self once she has the experience of delivering a happy, healthy baby.