In the ideal world, the ideal reaction you'd have would be to 1.
learn from this (and you have) and 2. continue to try - somehow- to
woo this parent (if for not other reason than at tax raising time we
want the parents to be on our side when once again the school board
But she does sound 'techy' and maybe 'touched' too - so yes, walk on
eggshells around her, be positive with her child at all times
possible -nothing woos a parent like the day their kid comes home
and says "I really like Ms. Smith's class- it's cool."
Many teachers spend their careers pointing out the problems - and
never understanding that ideally we should also be finding
solutions. Show parents that you really like kids and want them to
be successful in school.
Good luck - think back on this incident as helpful to you - I think
it has been. In the bad usually lies another bit of good learning
for the teacher if we're open to it.