My niece is turning 4. She is a very little thing and extremely girly -- loves pink, sparkles, unicorns, etc. She even picks out her own clothes and shoes and knows her shoe types. She actually once asked me where my "sandals" are -- at three years old -- and they were indeed sandals. 
I am not going to have any children of my own and this is my brother's daughter. She is also the only grandchild that three sides of the family has, so she is absolutely swamped in gifts for every holiday. It's kind of ridiculous. But these gifts are mostly clothes, fairy/princess stuff, and books.
Anyway, I have a couple of Tiffany necklaces I bought for myself that I wouldn't mind giving to her as a gift. To me these are very small, inexpensive pieces that I don't really want to bother with eBay for. And I know that the jewelry I love the most are the heirloom pieces or the ones with personal meaning -- I always wear the locket my husband gave me on our wedding day when I travel, and I have my grandmother's charm bracelets.
One of my favorite memories is my grandmother buying me a pin on bird with "a diamond" (it wasn't real gold and it wasn't a real diamond but it was soooo pretty to me). I considered it my first real piece of "jewelry" but for the life of me I don't know how old I was. Maybe 7ish?
So I would like to give her something but I don't know when a proper age would be. She is not going to break it, that I know. But would she appreciate it?
Can anyone give me some advice? I was maybe thinking her 5th birthday (next year?) Or should I do it when I go visit them in February for her 4th?

I am not going to have any children of my own and this is my brother's daughter. She is also the only grandchild that three sides of the family has, so she is absolutely swamped in gifts for every holiday. It's kind of ridiculous. But these gifts are mostly clothes, fairy/princess stuff, and books.
Anyway, I have a couple of Tiffany necklaces I bought for myself that I wouldn't mind giving to her as a gift. To me these are very small, inexpensive pieces that I don't really want to bother with eBay for. And I know that the jewelry I love the most are the heirloom pieces or the ones with personal meaning -- I always wear the locket my husband gave me on our wedding day when I travel, and I have my grandmother's charm bracelets.
One of my favorite memories is my grandmother buying me a pin on bird with "a diamond" (it wasn't real gold and it wasn't a real diamond but it was soooo pretty to me). I considered it my first real piece of "jewelry" but for the life of me I don't know how old I was. Maybe 7ish?
So I would like to give her something but I don't know when a proper age would be. She is not going to break it, that I know. But would she appreciate it?
Can anyone give me some advice? I was maybe thinking her 5th birthday (next year?) Or should I do it when I go visit them in February for her 4th?