Your image is 250x350 pixels. The dot-pitch of your monitor (92ppi) is irrelevant. The image will have a resolution in dpi (dpi - dots-per-inch - for printing, ppi - pixels-per-inch - for on-screen display) attached to it, and the 'default' is 72 ppi, but that's just a label (It's 72ppi for historical reasons - the dot-pitch of the early Mac monitors which were widely used for DTP, I think). If you change this resolution to 250ppi then Photoshop will tell you it's 1" wide. Change it to 10ppi and PS will tell you it's 25" wide.
You need to know the resolution that that the publisher requires. If it's for a magazine print, then 300dpi is common. If they want a 300dpi image to be printed 3.5" wide, then your image needs to be 1050 pixels wide (and 1470 high to maintain the aspect ratio).
So you're going to have to upscale your image from 250x350 pixels. If you don't you'll have to print at 250/3.5 = 72 dpi (there's that 72ppi again), which probably won't look good. If it's for web use, then it'll be fine.
But any time an image size is mentioned, you need to know both the dimensions of the image in pixels and the required resolution in dpi/ppi. The resolution required for good quality depends upon if the image is for web use (i.e. viewed on-screen) or for printing. Printing requires much high resolution for acceptable quality.