Where can Alla's friend find some photos of spring flowers?

Analysis:

The text states: "I remember you have asked me to send you some photos of spring flowers so that you can use them for your school science project. There are plenty of them now. I have taken some nice pictures and I'm going to upload them to my account so that you can see them on the Internet."

This implies that the photos will be uploaded to Alla's account and accessible on the Internet. Option 3, "on Alla's website," is the most fitting interpretation of "upload them to my account so that you can see them on the Internet," assuming her account is linked to a website or a publicly accessible platform.