Knuckle-cracking, like nail-biting, is a nervous habit that has been known to defuse anxiety. While it may be crazy-making to listen to, unless it’s a symptom of an underlying nervous disorder, the practice is relatively harmless. (In some people, it has caused swelling of the joints or swelling of the hands, so mention that to your daughter.)
Because you are sensitive to noises — which your daughter should already know — talk to her and her fiance and ask that when the impulse strikes, they walk out of earshot. Because they are living under your roof, they should respect your request.
What everyone is telling you is far less important than what your OB/GYN has to say about your situation. Because you have been married for a year without being able to conceive, both you and your husband should be talking to doctors. You may have a correctable condition that prevents you from becoming pregnant, or he may have a low sperm count. Distraction isn’t what you need right now; what you need are answers.
Smile at the questioner and reply, “That would be giving away trade secrets — but I can share one of them: I make them all with love.”