"I saw her at the library" is firsthand testimony.
"I saw her library card in her pocket" is firsthand testimony.
"She was at the library - Bob told me so" is hearsay. Just look at the word - "hear say". Hearsay is testifying about events where your knowledge does not come from your own firsthand observations of the event itself.
That's fair, I'll admit to getting it slightly wrong.
However, the original topic had nothing to do with that as far as I could tell, and instead was claiming it was hearsay for her to testify about her own whereabouts. That is simply not at all true, regardless of my error.
