File / Adobe Dynamic Link / Send to Encore.
The best quality will be using an x264 encoder in CQ mode to create a Blu-ray.
Next best is exporting using an H.264 Blu-ray preset for creating a Blu-ray.
After that, exporting a lossless file for MPEG 2 conversion using the free HC Encoder using CQ mode, which will end up on a DVD.
Last in the quality lineup, export using an MPEG2-DVD preset, changing the Min, Target and Max bitrates to 5, 7 and 9 respectively.
Avoid Dynamic Link.
That is solid advise for experienced people, but the OP has never burned a DVD in his life. Manually setting all the encoder parameters is pretty difficult, even for experienced people, as you have shown yourself with the 5, 7 and 9 bitrates. That is only a small part of the story.
Add the complexity of having shot in 24p and exporting to a 29.97i wrapped DVD and then the only sensible solution is using DL for this OP.
A fair point, Harm. But, she did ask for the 'best' quality. If she really wants that, she'll make the effort to learn about these things. At least now she knows about them.
That's a fair point too, Jim.