Hi Ken,
Ive done the Melbourne - Sydney run too many times as well as the Sydney Brisbane run and I would avoid the Pacific Hwy north of Hexham (where the F3 ends)
Depending on when she is leaving and the flood situation, I would recommend avoiding the western side of the ranges due to the risk of getting stuck....
Basically, A300 to Benalla, onto the Hume, follow that to Sydney, get onto the M7 (toll road- but you can pay over the phone if she has no tag), joins M2 (toll also), exit at pennant hills road, stay at motel that night (Formule 1 at thornleigh or another motel in Hornsby). Head north next day via F3 ALL the way to the end. Head towards Brisbane via the New England Highway to Toowoomba and head via North West of Brisbane as shown on the attached map.
Hume Highway is the safest and quickest way from Melbourne to Sydney and the M7/M2 bypass of Sydney is quite quick and well worth it, you wont get too much traffic.
This takes about 8-9 hours with stops at Albury & Goulburn as a suggestion to get to Sydney, so this is a good place to stop for the night. Heading north the next morning from Pennant Hills Road avoids a LOT of peak hour traffic and you are basically out of Sydney proper in 10-15 mins in the morning.
Go via New England Hwy as its a safer road, but not sure of the best places to stop for revive-survive as I normally use the Pacific Hwy.
Hope this helps, its longer, but I would say its easier, less chance of flood blockages and much much better for less experienced drivers, although she should always keep alert. Stops at Maccas are always easier and a good place for rest stops, coffee and a walk around.
Im not sure of the Toowoomba - Mooloolaba section, i just pushed it around Brisbane proper to avoid the traffic.
Hope this helps. I've linked the google maps directions I made in the picture below
Cheers
Chris
http://maps.google.com.au/maps?f=d&s...AXVov24Dg&pw=2