Many women have mild transient tachycardia in stressful situations.  I
think this woman does need some social support and a thorough medical workup
if this is occuring frequently.
     Many OTC medications can trigger tachycardias in susceptible women.  One
safe method to try to stop the tachycardia is for her to close her eyes, deep
breathe and gently press on both eyes through the lids for 4-5 seconds.  This
works for me and I have read that it stimulates a mild vagal response to slow
the HR. She can repeat it several times if she needs to.