Переклад - Іспанська-Афріканас - Quiero saber dónde estás mi princesita de cristal

I would suggest the diminutive 'prinsessie', which is about a dozen times more frequent than paraphrastic 'klein prinses'. Whatever you opt for, kristal must be joined to prinses. So it's either 'my kristalprinsessie' or 'my klein kristalprinses'.
mfG, Guido