Starting problem

My girlfriend has a 2006 Sequoia with a 4.7 V8. It's having problems starting. When the key is turned all it does is click. The battery reads 11.08v at rest. She said she's noticed it hesitating a couple days before it not starting at all. My assumption is it's the starter but I was wondering if anyone else has any experience or suggestions. Also the battery isn't bulging and visually it looks relatively new but I know that can be misleading as there's no sticker with a date on it.

11.8 is low for static. Check it when trying to crank. My bet is drops below 9. Bad battery causes the clicking. Have you tried to jump it yet?

So here's an update, I jumped the battery and it did fire up. Thinking it was the alternator and/or battery I went and tested the battery which came up bad with 2 bad cells. Replaced the battery and it started just fine but voltage slowly dropped from 13.9v to the point of the truck dying while on a test drive. My thought was and still is the alternator is bad. Had the alternator tested at autozone and napa which came out good so I'm thinking bad cables but connections and fittings are clean with no signs of corrosion. All ground connections are good too. Any suggestion or thoughts, getting a little frustrated.

Was the alternator bench tested or on the car? On the car is more reliable. Did your "battery light" come on during the drive?

The alternator was bench tested 5 times at two different stores all of which came back as "Pass". Put it back on the truck to have it tested under a heavier load and with engine on and it came up as a bad alternator. Bought and installed a new one BUT there still is charging issues. At idle voltage is just below 12v but under acceleration and cruising speed it maintains normal level (just fyi this is off the gauges on the dash). Again all connections and grounds are good and cables look good. Also, the CEL, TRAC off, and VSC light came on. Turns out there is a P0101 code which I think is an issue with the MAF. Gonna take it in and have a charging system performed and have a diagnosis done too. Any thoughts?

You actually need a voltmeter to check it on the car. Usually at idle 13.5 +. Rev it and should read 14. Turn on all electronics, high beams etc. Then measure voltage. Seen numerous bench testing good, on the car bad.