Can I marry a girl who is not very committed to prayer or the niqab, taking into account the limited options available in my city and my family's hope that she will change in the future?

The Prophet (peace and blessings be upon him) commanded marriage to the woman of religious commitment, for he said: "A woman is married for four things: for her wealth, for her lineage, for her beauty, and for her religious commitment. So marry the one who is religiously committed, and may your hands be soiled with dust [i.e., may you prosper]." This is also because a righteous wife safeguards herself, takes care of her home, and raises her children well.

Therefore, try to influence her and invite her [to righteousness] through your family or some of her mahrams so that she may become righteous. If she becomes righteous, then marry her. Otherwise, look for someone else, as there is no guarantee that she will respond or that you will not be influenced by her.