#1 was a late walker. I think we were almost stretching it when I called her a walker at 17 months. But I wanted to fudge it because I really didn't want her to have to be in therapy. (And now she is in therapy anyway, and I love it.)
When #2 had all of her hip problems I figured she would be jumping on the therapy train. I mean, really, she couldn't roll over until after 9 months. However, once she started rolling, everything just took off! She loves walking, and now often chooses to walk instead of crawl. She can walk the entire length of our apartment (assuming she doesn't trip on any of the toys along the way). She is still doing the stiff legged walk, but it is SO cute!
I often call #2 Zoots, and we have been very vocally encouraging as she is walking. Now when she walks, #1 often gets excited and says, "Good Walk, Zoot!" I love it.
#1 likes to mimic #2. She follows her around copying the stiff legged walk. I love that they are finally being friends and enjoying each other. Sisters are awesome.