[ Marriage & Divorce ] Open Question : TX married guy has wife (10yrs) & girlfriend &wants divorce. 3 kids. husb & gf are in military. should she sign or fight for alimony?

Wife has no money. Should she fight for alimony? Could she lose custody if they file divorce separately? Right now they are joint divorce same atty. But she wants alimony and her kids. can custody be granted to the husband and girlfriend if they marry? They are both in the military. Wife is civilian.