Everyone is compatible with everyone else, and I've had sex with more than 100 women. Some different, none not compatible, but some not very good at sex.
I fear this is what she was saying. There's a certain eros that most of us have, but some don't. It's quite hard to put it into words, but it's knowing and anticipating your partners moves, being in the right place when she moves, and just being in synch all the time, and feeding off your partners leads and just knowing what to do before it happens. I've had women like this, my wife is a bit this way, but it's not because we're not compatible but more that they (and she) just aren't much good at sex.
I say the distinction because my wife (and those other women) would be not that good at sex with any man. They weren't that common in my experience, maybe 3 or 4 out of more than 100.
How to get better? I think letting go, being 110% in the moment, and subconciously picking up your partners body language would be the solution.