Lavender didn't feel the need to linger on the Longfellow quote. Hermione had understood the reference and would take from it what she would. Sometimes it was just best to say things and leave them standing out there for the universe to do what she would with them.
"We did manage them in...well, in hard times before." It just felt different now because like she expressed to Michael there was nothing really keeping them together. If anything Lavender felt they were more splintered now. "Maybe we should practice then." It was a vague sort of asking because Lavender Brown never wanted to be asking Hermione Granger for anything. So, it was just like the Longfellow quote in the regard, left open for further interpretation.