Confused

I watch my god daughter everyday and love it. I have two boys myself but never experienced any of these issues. So I am wondering if I should be concerned.

To start she will eat anything! She takes her clothes off and will suck on her diaper. She will suck the urine out of it and if she has a bowl movement she will eat it. It never gets that far of course. I now safety pin her clothes on her or put her in overalls so she can't get to her diaper. I have to make sure that as soon as she opens her eyes from her nap that I am right there. She also eats nerf balls, garbage, paper, diaper wipes ect.. I have actually had to put the garbage in a closet and lock the door to keep her out of it. When she eats meals, she puts everything in her mouth at once, and is NEVER full. She acts like she is always starving.

She is very clumsy as most 1 1/2 year olds are. Although she will fall and land flat on her face. She never puts her hands out to catch herself. She falls very hard and it doesn't seem to bother her. She hits her head a lot, but will repeatably do it over and over. Example: if bends down to pick something up off the floor and hits her head on the table on the way down, she will scrunch her face, and do it over and over again.

She is very skiddish around people. She will be all smiles and run up to a person, and seconds later act like she is being hurt. She will scream as though someone is hurting her, and minutes later being laughing and fine. She also screams instead of talking. She has maybe 3-5 words, and mostly screams to communicate.

She will also sleep for long periods at a time. I will wake her after 4 hours, and she will want to go back to sleep with in two hours.

This seems like a lot, but I don't want to make a big deal about it, if this is just the way she is. Please help!