There is another female composer who has some albums filled with fully developed pieces. If you aren't familiar with
Michiru Oshima's works, you should take a look at her
discography (her 90s soundtracks feature more full-length pieces).
The soundtracks for "The Weathering Continent", "Legend of Casshan" (1st soundtrack specially) and "Hana Yori Dango" (1st soundtrack which is very classical sounding) should fit what you're looking for. Also her soundtracks for "Blast of Tempest" and "Fullmetal Alchemist" contain some pieces fully developed, but not the majority of the full score.