A week later, I decided to take a peek again to see how they're coming along. Lo and behold, there are now four! My friends started joking that we should throw some Cadbury eggs in there and see if Ms Robin would notice.
And below is what I found last week. I'll need to check in on them again to see if they all hatched. :) I've been hoping to get a picture of Ms Robin on her nest, but she gets spooked pretty easily; flies to the fence, or tree and chirps at me. Hopefully, she'll get used to us being around and won't attack me or anything. :P