I would email her and ask her to confirm her address, then send a letter with return reciept, its like 50 cents, then you can ensure its her address.
If it isn't, email her and ask her why.
Tell her the truth that you would either like to send her, her stuff. OR that you would like to meet with her, she and you both bring adults OR friends, and meet in a neutral place so you can give her, her stuff...

I would then take some time off, from relationship... and then find some one a bit more compatible.. perhaps
Carol