Made arrangements to meet and she closed call with, "OK, will it be fine if I call you back in just ten minutes?"

Me: "Cool."

Well, apparently, it wasn't fine, since she never called back. WTF???

YMMV, but caveat emptor. . . .

Seldom do they CB.  I usually take it to mean that for whatever reason they decided not to see you but don't want to say it straight out.