@Porg - I do like one aspect of it. It fits well to "the mother of invention is necessity". She smells like shit, so she invents soap.
I also like how it fits narratively too. Soap is relatively easy to make and something a lot of people know. Meanwhile there was a time in recent history where soap isn't as common (even if it is not completely foreign) despite the need and thus market demand is always there. Unlike some isekai where they somehow create a printing press or something with way too little effort shown, soap is something a layman can re-invent with relative ease while still being impressive.
Also, did you know in the 19th century, soap long invented, doctors refused to wash their hands before surgery. When a doctor tried suggest the idea to other doctors, they got all offended as an insult to their high-class gentlemen backgrounds where they are always "clean and pure" then dug their heels even deeper. It took germ theory and essentially the old generation of doctors to age out before it was truly accepted that they should wash their hands.