Your post confuses me. I can't figure out who it's addressed to. It might be addressed to her, but ... why would you even say something like that to her? It's completely unwarranted, even if you took it as an insult, and if you didn't, it's still, like, pointless really. Is she done with ... what, learning how to compose?
Which leads me to believe it's directed at me, but that doesn't make sense either, because TabIt has more than one track and different instruments. Unless you were talking about, like, writing for other instruments, like knowing the range of a violin or the various tambres of the flute. The range of a violin can be emulated easily in TabIt. It's a stringed instrument, after all. A violin's tuned to G D A E. It's easy to do. Also, Finale won't tell you when you're out of an instruments' range. Neither will TabIt, really, so there's not much of a difference there, really.
And the whole tambre thing doesn't really apply at all. MIDI is MIDI.
And actually writing for the instrument comes from experience, and the format you use to write really doesn't make any difference.
But hey, whatever, it all comes down to which one you're more comfortable with. I'm more comfortable with TabIt.