Muʾmin

This word is also one of Allah’s names. Ibn al-Qayyim says names that belong to Allah alone (al-Aḥad, al-Ṣamad, al-Khāliq and the like) may not be given to anyone. Names that are used of Allah and of people, such as raḥīm and raʾūf, may describe a person, but a person is not to be called by them in the absolute way Allah is. In practice the name is given without “al-”, or the ʿAbd form is used, as in ʿAbd al-Karīm.

• وَأما الْأَسْمَاء الَّتِي تطلق عَلَيْهِ وعَلى غَيره كالسميع والبصير والرؤوف والرحيم فَيجوز أَن يخبر بمعانيها عَن الْمَخْلُوق وَلَا يجوز أَن يتسمى بهَا على الْإِطْلَاق بِحَيْثُ يُطلق عَلَيْهِ كَمَا يُطلق على الرب تَعَالَى

  Ibn Qayyim al-Jawziyyah, Tuḥfat al-Mawdūd bi-Aḥkām al-Mawlūd, vol. 1, p. 127 (ed. ʿAbd al-Qādir al-Arnaʾūṭ, Maktabat Dār al-Bayān, Damascus, 1391 AH)

General guidance, not a fatwa. Ask your imam about your own family.