Hi Bibbygrace,
Mosquitos won't be a problem if you're sensible; cover up exposed skin (especially for the hour or so around sunset), don't eat on the JV's outdoor terrace in the evening, and keep your room door firmly shut, especially after dark.
Kettles were a bit hit and miss when we were there, but a modest tip in advance to our ro om cleaner and a tray appeared very promptly afterwards :)
I'm a coffee snob.
The espresso provided in the restaurant at the JV is very good, but be aware the coffee powder and (especially) the non-dairy whitener type product provided in the rooms is truly horrible.
Take some Gold Blend and Coffee Mate from home (or tea bags and your favourite whitener)
The call to prayer at sunset is one of the haunting features of a holiday to a Muslim country, and the calls from the West Bank can be heard drifting across as you watch the sun set over the Nile.
The sound isn't intrusive at all, and couldn't be heard indoors with room doors shut. You won't be woken up at 4am!
Karnak is an easy taxi ride away, as Phil explained above. Luxor Temple can be accessed easily from the JV's free shuttle bus (or boat), as can the excellent Luxor museum.
I'd just add that it's VERY easy to tour either of these temples by yourself with a good guidebook .. so I'd suggest you don't book a tour or a guide unless you really want to hear the family tree of the ancient rulers recited in mind-numbing detail.
Luxor Temple is great to see by floodlight in the evening .. that's when the locals visit, so it's also a great place for people-watching before going on to a restaurant for dinner.
Our teenagers found the best bit of the holiday was exploring Luxor itself .. much more interesting than tombs, temples and dead dudes. Once you get away from the hotel quarter there's very little hassle and lots to see.
I'm sure your 14 yo will also enjoy it and want to go back.