It is not permissible for a woman when praying to wear tight clothes that forms her `Awrah such as pants or trousers. Even if a woman goes against this ruling and prays wearing these tight clothes, her prayer is still valid, because what is required is to cover the `Awrah, and she has done that.

It is not permissible for a non-Muslim to pray either in the ranks or on his own. What he has to do is to enter Islam before he prays, then to purify himself by doing ghusl and then fulfil the conditions of prayer.