>>24626439Not the anon but this occurs right after Duncan Idaho is gifted to Paul as a ghola by the Guild, specifically as a honeypot for him and his sister. She is using a training dummy while naked (turned up to difficulty 11, which it shouldnt go past 6) until Paul disables it, walking on on her with Stilgar (I believe?).
Paul does in fact react to the sexual appeal of his sister which is foreshadowed by the Bene Gesserit's scheme to potentially breed Paul with Alia for their breeding program. So yes, she is naked and Paul gets horny about it. He also comes back to the thought with his prescience.
The pages right before this describe her 16 year old nakedness, musculature, etc. She has a good body BC she has Bene Gesserit nerve control (before book 3, where the abomination arc reenters the story).
If you think that's weird wait until you read god emperor