However, the serum electrolytes, which often show a hypokalemic alkalosis in mineralocorticoid excess, aren't helpful in this case. Also, the physical signs of Cushing's sydrome (and the hyperpigmentation that may be present in Cushing's disease) are minimally present, if at all. This could indicate a relatively early Cushing's, or another etiology for the patient's problems. Other causes for hypertension in a young woman (e.g. renovascular disease or pheochromocytoma) should also be considered.
Remember that depression and confusion with a puffy facies can also be compatible with hypothyroidism (though a heart rate of 90 would be unusual in that setting), and depression in general following childbirth is not uncommon.
The bottom line is: we really need more information before narrowing the differential too much.