Keep it simple. Park at Birches Valley, earlier the better.
Ride Follow the Dog as signposted. Yes High Voltage and Bombhole are closed but the diversions will take you along high ground and parallel to Marquis Drive.
Tackeroo campsite will be busy because of the demo day but not impossible and then you get the descent all the down from Tackeroo to the end.
For a first time ride finishing with a long climb isn’t ideal and is unlikely to leave her enthused about coming back to ride it again.
I’d expect the whole hill back down Tackeroo to Birches Valley to be busy with the increased traffic due to Leisure Lakes so be prepared to stop at suitable points to let the warriors go past.
Then to finish take it easy over the rock rollers if your daughter isn;t used to this kind of thing as it will be easy to take too much speed into them and end up airbourne.