[Sonic dB]

Tell her to take 101 all the way down... at one point she will cross some hills just south of Camarillo...at that point, about 10 miles down is Las Virgenes Rd. Tell her to get off at that exit, and take that windy road around the mountains down to Malibu. Its about 7 miles from the 101 through Las Virgenes down to Mailbu...very easy and sort of scenic drive. When she gets to Malibu, Las Virgenes Rd. will be called Malibu Canyon Rd and she will pass Pepperdine University on her Right...this will take her directly to PCH (Pacific Coast Highway) where if she turns Right will take her to North Malibu and to the Left, will take her into the main part of Malibu and South on to Santa Monica....this is the more logical way to go but make sure she checks MapQuest first.

She could also take Highway 27...which is also known as Topanga Canyon...however that road is much further South on the 101 from Las Virgenes and will take her down to the Southern part of Malibu, closer to Santa Monica... Its also a much windier road and I wouldnt recommend it in the dark at night...
In addition to this...there is not a clear cut way for her to get to 27 from the 101...she would need to exit on Ventura Blvd...take that down about 1 mile, then turn right on to Topanga Canyon Rd...go down about 4 miles until it gets out of the residental section...at which point it turns into a twisty, dark, mountain road for about 10 miles down to Malibu....
I completely would not recommend this to someone who is not familar with the area.

To get to OC from Malibu...just tell her to take PCH (Pacific Coast Highway) South through Santa Monica, at which point it will split and she will want to veer to the Left to get on the 10 Freeway...she will be on the 10 for about 2.5 miles and it will then take her right to the 405 South...this is MUCH easier than the route that you suggested above...