luvFclass:
1) She arrives in Terminal E. The LX F lounge is in Terminal A. The exit is in/at Terminal A, anyway, it's not a big detour. Pretty easy, just take the Heidi train (only connection, anyway) to Terminal A, then follow the signs which read "Connections" (not baggage) - once in the regular Terminal A (departures) just follow the signs to the LX F lounge.
2) This one SHOULD work out, as she does arrive on the same day with LX F. If you only depart on TG F, you can only access the SEN/Business lounges. But as she had a valid arrival on LX F, even if she visits the lounge for the second time on that day, it should work out. Never tried it myself, though.
3) Very, very easy. She just follows the signs "trains", buys a round-trip ticket (24hrs, unless she can squeeze it in 2 hours
) to Zurich (Zone 10, 21) on any ZVV ticket machine, then proceed to take any train (S-Bahn or any other train, it's very easy to see which ones are going to Zurich Mainstation) - once in Zurich mainstation, there is plenty to do. On a nice day I would recommend a boat ride to the lake from the main station, then walking back along Bahnhofstrasse to Paradeplatz (where Sprüngli's "original" cafe is) - from there, she can further walk to the main station or take a tram. All public transport within Zurich city is included in the "ZVV Zone 10+21" ticket she buys at the airport.