If mother experiencing hairloss has baldspots, it is possible that she has a
form of alopecia that can be brought on by stress.  It is an auto-immune
disease that can come on suddenly (I have psoriasis, which acts the same way,
comes and goes when it feel like it).  She would have to check with a
dermatologist to be sure.
  I have a good friend who had this type of hairloss as a freshman in
college, also a month before her wedding, and following  the births of both
her children.
  Lisa Jones, LLLL in South Florida