Hi i'm a 38yr old female who was diagnosed withsheehans syndrome beg 2008,11yrs after i haemorraged during childbirth(it took 11yrs for diagnosis!!)as you know you have no pituartry gland and i now rely on medication to do all the jobs that should.I have had terrible trouble with my thyroxine as when i try to increase it i get palpitations and irregular heartbeats.i take steroid tablets and hrt.i gat regular attacks of swelling in tongue,chest area and down left side of body,i see an endocrinoligist every 12wks as i hope your mum does.dont know if this helps as its only my story.
Found this, may be can help
http://www.mayoclinic.com/health/sheehans-syndrome/DS00889/DSECTION=1