Translation:I hope you are wearing a sweater over the shirt.
I looked up the meaning of blouse, and one definition that seemed right was: a woman's upper garment resembling a shirt, typically with a collar, buttons, and sleeves. “Resembling a shirt” implies that a blouse is not always a shirt, and in any event, it’s generally agreed that a blouse has an unmistakably feminine appearance. The female in question in this sentence may not be wearing a blouse, so it’s safer to say shirt. By the way, I don’t seem to hear the word blouse much anymore among young people … does anyone else think that it’s becoming an old-fashioned term?
Substituting a specific word for a general word will get you into linguistic trouble. Jumpers and pullovers are certain kinds of sweaters, but they are not cardigans.
If the word to be translated were “people”, would you use the word “women” to see if it is accepted? If not, then you shouldn’t use jumpers and pullovers to mean sweaters.
I do not agree with you, Theresa 754142. A cardigan is not a sweater. A cardigan is a cardigan. Pullovers and jumpers are generic garments that are pulled over the head and, as such, the words are interchangeable. The word "Sweater" to describe such garments is a more recent UK import from American English. Conflating your argument with "people" and "women" is fallacious. I refer you to Google.