Isekai manga about a woman transported into a VR game based on a novel she wrote

Question

The main character creates a VR game where you can create different worlds, she creates her own world based on a novel she created, then she gets stuck inside unable to leave the game

• It is a fantasy setting, can't remember if there is magic or not.
• She is stuck inside the game, so yes, there is a game interface
• She is stuck inside a minor character of her novel
• I think it was in colour but my memory is playing tricks on me
• More romance/some
• Red hair
• She crossdressed to get into a mansion to work there (near the middle of the story the male lead finds out that she is a girl, at the same time she is finally able to leave that world because a portal opens up/how you log out, and she wakes up in the hospital and continues her life until she pulls out the novel that she created/one she created in the game and finds out it's been altered to what she did in the game; she then goes back into the game to live there forever)
• When she goes back into the game she tries to find the male lead but finds out that the whole mansion thinks she's a spy for another kingdom because the other kingdom attacks right after she disappears

Answer 1

Is it I Choose the Emperor Ending?

Obsessed with medieval fantasies, Marina develops a revolutionary VR device that can bring fictional worlds to life. Her dreams come true when she transports herself to Lasnorok, the setting of her own novel. The problem is, she can't get back out! Disguised as a runaway slave boy named Rino, she comes face-to-face with the main character she created, the ambitious Edward Allen Dihas. Can Marina help him overthrow the emperor and survive to make it out alive?

The description seems to be fairly clear cut.

• It is a fantasy setting
• She's stuck inside the VR world she created. She tries to log out after being captured as a slave and is unable to do so
• She seems to be just a minor character, but I haven't read far enough to confirm this.
• It's a full color webtoon
• Tagged "Romance"
• I'm not seeing any red hair so far, so that's a miss. Neither Marina's real-world hair nor in in-game hair is red. The ML has black hair, but red eyes.
• She is initially mistaken as a male slave and captured. I don't think this was intentional. Can't confirm any of the later details in this point.
• Haven't gotten far enough to confirm this point one way or the other.

Answer 2

Could this be As You Wish, Prince (warning, TV Tropes site)?

As You Wish Prince is a Korean fantasy romance webcomic published in English By Tappytoons. Yoonsoo is the successful author of a popular fantasy series. Just as she’s about to start work on a new series, Imperial Prince Einzen Kyte, the worst villain she created has kidnapped her into the world of her own story?!

It has a redheaded author transported to a world based on her works. According to subpages, she exits and re-enters the world, and finds that the changes she makes outside of the world affect it (although she can freely manipulate herself within the world, which she initially does to increase her breast size). She takes up a role as a guard at the palace, not certain if she crossdresses to do so.

Under things that don't match, after starting reading, the "third prince" shows up in our world to initially kidnap her rather than her showing up via a virtual reality machine.

Found via a search for isekai manga author, which led me to this Reddit post.