Why does my UI look different after others edited the project?

I was making a 2D platform game for my final year project. And every time my group mate edited the project on her own computer, I found out all the images changed their sizes and didn’t fit on mine at all. Every time I fixed it and then my group mate opened it everything became all a mess but she said everything looks fine on her computer. This is driving me mad cuz she kept telling me to fix it but then she just opened it again. What could I do to solve this problem? Why everything looks fine on her computer but not on mine?

Show us screenshots before and after problem.
Why you sending to your colleague project then getting it full back? You should send assets as updates to committed work. Or simply use git repository and share with colleague, if work is strictly code related. Unless she works on UI? Otherwise, is no need to get whole project back from her.

What numbers are actually changing? Are the differences in the original image file, the import settings for that asset in Unity, the component that’s displaying the image in your game, the transform of the object that component is attached to? Something else?

Are you both running the same version of Unity?