Is wearing a bra at a young age permissible or forbidden, and what is the evidence in case it is forbidden?

A Muslim must cover their 'awrah with something that does not describe it, and it is disliked to wear clothing that accentuates the 'awrah. As for wearing a "bra," there is no objection to it if worn under a covering garment. It is disliked if it is visible, and it may be forbidden if there is a fear of temptation. All of this applies specifically to adult women. As for young girls, it is not forbidden for them to wear it unless it accentuates the 'awrah without another garment over it, in which case it is disliked, and it is not forbidden unless there is a fear of temptation associated with it.