I have both zippered and pull on hoods. My zippered hoods tend to be of heaver rubber. As mentioned, both have advantages. I prefer the pull on hood for over-all snug fit but the zippered ones are definitely easier to get off in a hurry.
Hoods can be a little scary for first timers. Sounds like you are lucky enough to have a budding rubberist in you lady friend. You might want to take it a bit slow and work up to win her trust. A zipper does give the wearer a sense of security in case they wish to bail out. Panic in a pull on hood is not fun. I suspect a lace up hood could be even more horrific.
Just a thought