If the pattern is actually online and free (based on one that's been around forever), I would tell the person the name the pattern is listed under, and she can look it up for herself to get the yardage or buy the current pattern for the instructions and templates, I don't see anything wrong with that. If it's a new original pattern, then she buys it.
If I recognize a pattern like Irish Chain, and I can figure it out, I would never buy the pattern.
I just played with Broken Dishes. Lots of information here:
http://www.earlywomenmasters.net/qui...broken_dishes/
Quite interesting when done.