Gregory's Server
In English, we don't combine adjectives (description words) and nouns (people/places/things) into one word like some other languages do. Trans is an adjective that describes the noun woman. It's the same as saying "tall is an adjective that describes the noun woman". It's not correct English grammar to leave out the space and call someone a whitewoman or a shortwoman. You put a space in between the words to indicate that white or short are describing the woman.
Trans is an adjective that describes what kind of woman a person is.
When someone says transwoman, they're indicating that a transwoman is not a woman, she's something else.