Well, it does have something to do with that sentence, since we both understand two different things from the same words. It's a further argument that it should be deleted.
I just meant to point out that in saying that "the report actually DOES NOT show two family lines at the same time", you're using "family lines" in a different way than most genealogists and family historians even. The term line in the context of a pedigree generally refers to a line of descent or ascent, a lineage, a line connecting an ancestor to a descendant, a bloodline. A pedigree populated with a few generations, therefore, displays as many bloodlines as there are lines connecting the proband to each progenitor. In other words, it does indeed show two or more lines, as long as the parents are known.
And that's the whole point of the pedigree and why it's so popular and frequently used (in the Ahnentafel format).
"4 lines or the 2nd generation"
Yes, the people per generations increase exponentially*, but the lines only increase by 1/2 per generation as you step back either patrilineally or matrilineally. Yes, there are four lines in the second ancestral generation, but half of those were already accounted for in the first ancestral generation. If you follow the Ancestral Lines numbering scheme described above, you'll see what I mean. It's why I recommend that FTM add it as an option for ancestor reports and charts.
*caveat: it doesn't take long going backward on your pedigree to exceed the real human population at the time, so we're obviously all in-bred.
"I think you would not consider her a separate family or family "line" just because she has a different surname than your father has"
Yes, I do. Think mtDNA vs. Y-DNA.