Will a palate expander work for me to fix a cross bite? an orthodontist who specializes in appliance recommends i get it while another orthodontist recommends that i do not miss with the cross bite because of my age?

At your age, the median palantine suture has fused. A palatal expander has little chance of separating the bones of your maxilla. Movement of the teeth may be more realistic depending on the extent of the crossbite. A local orthodontist who can examine and treat you is better prepared to advise you.

Cannot speak to your specific problem. In general, if upper jaw is too narrow it should be widened so that teeth can fit properly. At your age widening may require surgical assistance and/or a TAD supported appliance.