My brother sent me a photo of the nieces wearing cardigans I made them. Niece the Elder's tiger jacket is almost two years old and still fits her (she just turned six), which is great, because it was a lot of work! It looks like it will fit for for a little while longer. As you can see, she is really into the whole tiger thing.
Niece the Younger's panda cardigan has only been hers for about a month, so it's just as well it's a bit too big for her. I'm glad the collar seems to want to stay down. She will be four soon, so she should get another season, maybe two, out of it.
Both of them got "pitched" on the cardis before I made them for them. I still maintain rule #1 with DIY gifts is to get at least some opt-in from the recipient before making anything, unless you are very sure they are going to like what you're making.