I ran three marathons between 2:48 and 2:42 in the course of five months back in 1991 (also female). My marathon progressions for the year that included those three were:
October 1990, 3:08 (should have been about 3:04 but took a wrong turn 2 miles before the finish)
January 1991, 2:53 (at Houston)
Early May 1991, 2:45:16, just missed OTQ
Mid-June 1991, 2:47:xx
October 1991, 2:42:50, got my OTQ
I was running 75-90 mpw. Typically ran in the early morning every day, most of it pretty unstructured running. Typically I would do a double one weekday, with the second run being a track workout, quarter-mile or occasionally mile intervals. Weekly long runs of at least 16-18 miles and up to about 23.
I got injured in December 1991 and was never the same runner again. Good luck in Houston and enjoy it while you can!