Yes, getting off of Maggie's leg right now would only invite you to being noticed more easily. With the conversation currently being about tiny people, an eighth of an inch tall bug on the floor would draw the attention of every person in this room.
So, you turn your attention back to your previous goal: walking along the skin of Maggie's leg, get to her waist where you can rest without danger of falling when the girl stands.
"Okay," says your host, still desperately searching for a way to entertain her cousins, "what would you do, if you were shrunk small? Where would you go, what adventures would you have?"
"Ooh, that's a good one," Ethan says, turning his mind to an answer. Well, this may actually be interesting, you tell yourself, as you pass the minor hill that is Maggie's kneecap.
Then Maggie's hand slaps down, the sound of skin on skin impacting directly behind you throwing you across her leg as well as out of your reverie. Turning, you see that the girl's finger is now idly scratching at the path you walked - she felt you, and needs rid of that itch.
The fact that you haven't been swatted means she's not looking down, just dealing with an irritation she feels. Good. As you watch, the immense hand settles down to rest, Maggie leaning on her knee as she presses Ethan for an answer to her question. An otherwise dainty body part, now settled like the base of a tower, supporting countless tonnes of human.
This is an opportunity: you could climb onto Maggie's hand for a quick lift, since if you continue walking along her she may feel you again.
Of course, you could just stay here and listen, not moving while these kids go through their own ideas of shrunken survival. Then again, you could take Maggie's blow as a warning, and hop off of her to the carpet to continue your journey.
All those options being risky, maybe you could finally reveal yourself, shout up to the giants? Risky in itself!