Moe
I am not from VA, but I believe the following to be true. I am no LEO or lawyer.
If by "tear gas" you mean CS gas (ortho-chlorobenzylidene malononitrile), I don't believe this is readily available to the public.
If you mean "pepper spray" (Oleoresin Capsicum gas) it is probably legal for you to possess. I cannot believe it would be illegal for a 16 year old girl (or boy) to possess pepper spray. It may violate the rules of schools or other places.
http://leg1.state.va.us/cgi-bin/legp504.exe?000+coh+18.2-1308.
A stun gun will probably raise some eyebrows and is really not too good as a defensive weapon. It is an effective offensive weapon. If it is used as an offensive weapon by any civilian, the result will probably be arrest and prosecution.
Research the statutes/laws of your state pertaining to minors and weapons, and weapons in general. These laws are availabe on line free at the site provided by Blues. If you cannot find a statute that prohibits an action or activity it is not illegal. Then before you do anything call your local law enforcement agency and ask them. If they say they would arrest you for carrying the items mentioned, ask them to provide a statute/code/law number for you, ten read that law to see how it applies.
Here is a start
There are alot of laws that apply, your research should take a few HOURS, not minutes.
