Casual Sunday Brunch near Santa Ana?
How about Chomp Sushi's Hawaiian brunch? It's in downtown Fullerton, so you'll be driving further than she will, but on a Sunday morning (they open at 09.30) there should be no traffic at all. It's not on the 5, but just off the Harbor exit of the 91.
The food is very good -- we had our daughter's christening brunch there a few months back -- and the price, $25, is pretty good and includes champagne and a couple of champagne cocktails.
If you're willing to drive further into OC, though, the reigning queen of the OC Sunday Brunches, in my OH so humble opinion, is at Taco Rosa in Newport Beach. YUM... and for $15 you simply can't beat the price. www.tacorosa.com -- go and drool.
Chomp Sushi & Teppan Grill
181 East Commonwealth Avenue, Fullerton, CA 92832
2632 San Miguel Dr, Newport Beach, CA 92660
Leaving your woeful geography aside (a great deal of the city of Los Angeles is, in fact, south of the 10), I have to say that on the "normal" route from Hollywood to Santa Ana, there isn't a whole lot. There is, of course, if you're willing to deviate a bit from the "straight-line" route down the 101 to the 5, a wealth of insanely good dim sum in the San Gabriel Valley, but that will put the bulk of the driving on your friend from Santa Ana.
In addition to my recommendation below, there's also Taps in Brea, which does a very good Sunday Brunch... again, not exactly on the way from Hwd to Sannaanna, but perhaps worth a detour.