Don't worry too much about it. She'll land in 2E and it doesn't really matter where because you go through immigration before anything else. From there, just follow signage for connections to 2F.

If you really want to know how it will look, use this:

http://easycdg.com/passenger-informa...o-terminal-2f/

I think the estimated times are a little on the high end. 90 minutes should be totally fine. Remember, you don't need to claim and re-check your bags, that's done at the destination when you're in the Schengen zone.

The only time I'd say 90 minutes isn't enough is when going to 2G since it's a totally separate building.