[quote=@Prince of Seraphs]
<Snipped quote by ProPro>

How? If the encounter was so quick is was barely perceivable how did she figure out what happened?
[/quote]

It's not like the Speed Force is a well researched scientific exploit, and it's too bad there isn't an entire museum dedicated to its chosen conduits. :P Once her whole life became slow motion and it began taking weeks to walk to the grocery store, she had plenty of time to figure that out. What with her powers manifesting as a whole.