Is my request to my fiancée that she not sit with her young male relatives, and that she not answer the phone if there is someone else to answer it, considered fanaticism or a necessity in this day and age?

If the relatives are not mahrams to a woman (such as the sons of her paternal uncle, paternal aunt, maternal uncle, and maternal aunt), they are to be treated like strangers. Therefore, khalwa (private seclusion) with them is not permissible, nor is shaking hands with them.

If there is a necessity for a woman to sit with them, she must adhere to hijab, lower her gaze, avoid being soft in speech, and limit her interaction to the extent of the necessity. It is preferable for men and women to sit separately, each in their own gathering.

It is permissible for a woman to answer the phone or the door, provided she does not soften her speech. If her voice is beautiful and alluring, it is preferable for her not to answer.