It is understandable that you may be concerned about the situation you observed with your sister-in-law. However, it is important to consider that every pregnancy is unique and women may carry their babies differently depending on various factors. It is also essential to respect the privacy and intimacy of others, especially when it comes to topics as sensitive as pregnancy.

If you are genuinely concerned about your sister-in-law’s well-being or have questions about her pregnancy, it would be best to approach the situation tactfully and sensitively. You might consider asking questions in a respectful manner, expressing your concerns compassionately and offering support if needed.

It’s also possible that there are perfectly innocent explanations for what you observed. For example, some women may have variations in the size of their belly during pregnancy due to the baby’s position, body structure, or other medical factors.

In all cases, respect for privacy and family support are essential to maintaining healthy and harmonious relationships within the family. If you have serious concerns, it might be helpful to first discuss them with your sister-in-law herself or other family members involved in the situation.