I am always in favor of balance and compromise. However, I do not believe you are responsible for funding her "retail therapy". Having a crisis in your M is not a legitimate excuse for spending yourself or your spouse into penury.
As I stated before, if she or your children have legitimate needs, find ways to help that do not enable bad habits. If she simply feels she needs that extra pair of pumps to feel better about the situation, then I am considerably less sure unencumbered largesse will move either of you to a better place.
