Nice job! First things first, the photos are slightly underexposed. I would use an ISO of about 200 and a shutter speed of 300. If you have a good editing program, you could edit them there. The next thing I see is on the third photo. The lamb isn’t perfectly centered, so if you could crop that slightly, that would help a lot.
Wonderful job on capturing the snowflakes in the background! It really adds to the photo!