The Sirrus and Crossroads are very different bikes. I'm not at all surprised that the Sirrus rides easier. The Sirrus is pretty much a flat bar road bike. Very light and nimble, with a more aggressive riding position. The Sirrus probably has a lower volume tire with a higher maximum inflation. The Crossroads most likely has a suspension fork, that you can hopefully lock out when road riding. They're just two totally different bikes.

No lock out function since it's lower end.

For now when we ride distance together we trade bikes (she got a men's crossroads since the only different was the dip in the frame)

Same here. My targets are usually moving right along, sometimes in pacelines.