I probably would be a good idea for this mom to have a physical exam by her
health care provider just to be sure.
The exhaustion is mostly likely just from caring for two small children.
 Simplifying her life by cutting back on outside activities for a little
while and reducing  her expectations for housework.  Does she have a
supportive environment to give her a break every once in a while?   La Leche
League discusses this in one of their meeting topics.  Having her meet others
going through the same things may be very helpful.  She can find a local
group by calling 1-800-La Leche.
Ruth Solomon, RN, IBCLC, LLL leader and tired mom of 6