I'm not sure that my five-year-old self would know what to make of me, although she'd probably be pleased to know that I still draw and play the piano. However, she would perhaps be vaguely disappointed that I am not, in fact, a ballerina. I don't think I was thinking much about what I wanted to be when I grew up at that age, but like many little girls, I did enjoy the idea of being a ballerina. More than anything, though, I think I probably just wanted to be a mermaid.
I lived in my own strange world back then.
I've actually entertained a similar idea to this in the past. In my case, though, I've wondered what my pre-teen self would think of me. I guess because I was old enough then to have a clear idea of who I was and what I wanted to do, but young enough that quite a bit has changed since then. I wanted to be a marine veterinarian or marine mammalogist, because the idea of working with and helping marine mammals was highly appealing. It still is, but I ended up deciding on a career in art instead, which would not likely be surprising at all to my younger self.
I think younger me would be a bit appalled by some things, though. While my sexuality has never actually changed or wavered, I was happily in denial about it until my last year in junior high (and even then, it was a struggle to accept it). I come from a conservative Christian home, and my family was very clear about their views on homosexuality. My younger self would not be happy about that. She'd be extremely upset by the fact that I'm not a Christian, and probably torn between bemusement and horror by my preoccupation with slash fanfiction. :p She'd be disappointed that I'm still dealing with many of the same health issues that had only just begun for her. And it would be best not to mention my teenage years altogether, because I don't think my younger self would be able to handle that.
If I were to offer any advice to my younger self, I'd probably tell her to not accept anything as truth simply because she was told to, and to always keep her mind open and curious. I would tell her that she is better off just being herself and not wasting time trying to be something she's not to fit in with other people. Finally, I'd probably advise her to be careful about who she chooses to trust, and not to take everything at face value.