Have your daughter take a look at Adobe Premiere Pro on their "Creative Cloud" - it's a $19 monthly subscription for what is probably the best of the "prosumer" editing software available today.
- just make sure her graphics card is one of the Adobe recommended cards
Adobe saw Apple abandon all of us (when they left FCP 7 and when to "X") and they put some mojo into Premiere... many editors I know have gone to Premier from FCP 6 & 7 and now swear by it - and some describe it as FCP 8 - because the interface is so similar to the older versions of FCP.
Rendering is GREAT in Premier - you can keep working while your machine renders... as opposed to being down while your machine chews away (as in the FCP world)
FCP 6 (and 7) are not supported by Apple anymore - no more updates EVER.
- those of us with hundreds of projects cut on FCP 6 are stuck keeping an older system around to run 6 with - just in case our clients need a revision done on an older project (as just happened to me last week)
Before your daughter starts cutting projects on an "abandoned" program - that newer Apple computers won't even run - maybe it's better she puts her version 6 on EBAY and goes with Premier.
There's a real possibility that all this stuff you are trying to do now to make yesterday's software run today will just come back and bite you tomorrow.
My first Apple was a Mac 512K (bought it in 1982 I think) - I've been loyal to Apple - but with this FCP deal they sure haven't been loyal to me... to any of us. Check out Adobe Creative Cloud - look at the support and updates offered - and compare that with the fact that Apple no longer supports their earlier versions of FCP.