If you mean the file size on disk, that different than the image size itself in Megapixels. But I can asnwer half and this is quick and easy.

If the photo size is too large because you scanned them at a high resolution. Make the photo smaller before you add it to the DOC file. Even though it's only as wide as the page or where you pasted it in, the file will have all the pixels of the original. Make it 1000 wide or smaller.

Also the save could be at 100% instead of 80% (or level 8 on Photoshop or anything else) Save Quality 100 or 12, which will also make a huge original photo because of the resolution and fine pixels.

Free Photo Editor - Irfanview, install the software and the plugins: https://www.irfanview.com/

If you mean the final file size, the word doc is too large, you will need to ZIP or Archive the file to send it.

All else fails, please email me.