Hi Leah, If they are very large you might have to go back and reduce them even again. The pictures I reduced for you I believe I reduced them by 50% to start, then I cropped in closer to the goats (you don't have to do that I just did) and I reduced them again by by going back to stretch/skew on the already reduced picture. The second time I reduced them by 40% (I went back and put 60% in the boxes) I usually only have to reduce the pictures my camera takes by 50% once, but your camera takes very beautiful, detailed pictures so the file size is quite large so I had to reduce them twice. It is one of those things you have to play around with until you get them the size you want. But I will give you a few ways of seeing what size your picture is in demensions and KB though.
One easy way to see if they are small enough is to reduce the picture and go ahead and save it. Then go to that file on your computer and rest your pointer arrow over it and a yellow box will come up that will say it's deminsions. Or you could right mouse click on the picture file, which will bring up a drop down menu, go down to "Properties" and click on it. This will bring up the properties of the picture and with that it will tell you in KB how big the picture is. Depending on the picture but ususally if it is less than 50 or 60KB it is going to be small enough. After you do a few you will just kind of get an eye for if they are going to be small enough by how large the picture appears in Paint. I hope that helps, if that doesn't work for you let me know and I will help. Or feel free to email pictures you want reduced in size to me, I am happy to do that for you too.
PS- another easy way to see the size pictures on your computer are is to go inside the folder where you keep your pictures at. Go up to the funny looking little box icon at the top after the "Back" "Search" and "Folders" icons. It has a small black arrow beside it. Click on that arrow and a drop down menu will come up that says thumbnails, tiles etc. Go down and click on the word "Details" in that drop down menu. This will change how your files appear in that folder from icons to a list with the "details" of each picture. Including the size and demension.

If you want to change it back just go back to that box & drop down menu and click on what it was set at before.