What Tabris said. Seems like she's pitching it to the wrong editors, especially if not one sounds excited or wants to read, but definitely if they seem confused about the premise. Also, I had an agent who didn't give me sub details no matter how often I asked her. We parted eventually and I now have an agent who tells me as much as I want to know, and then doesn't have to be pestered and reminded of how much I want to know/updates.
A few months on sub isn't long enough to be considered "dead in the water". That's horrible to say! Some authors don't sell for 15 months! And it's surprising that she only has one round (?) of small amount of editors to sub to. Is your ms very niche? And while it's good to have an honest agent (to tell you it might be closing that time to call it quits), it's not good to have a pessimistic agent. They need to believe in your work and love it to sell it to the right people. Every time I get a pass or ask my agent if she thinks we're near the end, she always says there's x amount of editors left, it only takes one yes, we can still find that one editor who'll love it as much as I do, etc. She won't call it quits until the last editor responds.