Always good to get an email like that. Sounds like mom either did some research or talked to friends with kids and found out it is more normal than she thought.
As with so much one of the signs of abuse or a bad daycare situation is your child cries at drop off and that will be on any list she has read so of course when tears happen she was ingrained to think the worst. Some kids just cry cause they want to. Glad the parent is feeling better.