I had to go back and read my own post. Thought maybe I named you. And you know what? I didn't.
The overwhelmed feeling could have attributed to her being so upset. Besides, you don't know how it affected her choices or what happened.
I am aware of what happened, I read the OP. I don't think he ever said she thought they were one and the same. A lot of people let their pay go to their savings account and then only transfer what they need to checking. Since these were set up as automatic withdrawals, perhaps she didn't see the need for the extra step because she forgot, didn't realize, wasn't told, whatever that she was limited to 6 withdrawals a month. Since this has never happened to her before and she has been doing it for awhile, I can see where perhaps being a little overwhelmed with all the new expenditures, she just missed it that there would be more than 6 or that now there would be a problem.
People do allow automatic withdrawals from their savings. Usually more of the every 6 month type things like insurance but I know several people that do that. That way it doesn't slip their mind and totally mess up their checking account. So they are most certainly designed to use for automatic payments/withdrawals.