It looks like STL doesn't have as many pendant ocarinas as before. Most of the ones it sells now have some kind of theme. I can't really decide on a personal favorite, so I will just tell you the pros and cons of some pendants I own.
The necklace ocarinas are fun, pretty, and convenient to carry. Whether or not she will enjoy one depends on how she feels about sopranos.
Some other pendants I have are the LoZ shield and the soprano rupee.
The shield is fairly easy to play except for if you try to use the fipple bend, because the mouth piece is at an angle.
The rupee is easier for the fipple bend, but the B note is less accurate. The B fingering on my rupee plays just shy of hitting C, so I have to overblow on the fingering for A flat to get B.
The 4 hole dragon egg has a soothing sound and its light breath pressure is easily manageable. However it has a limited range, and its hard to get a good seal over the large finger holes.