My girlfriend is a Peruvian citizen living in Peru, and I'd like to have her visit for a few months. She has never been to the US before. She probably can't muster the finances to demonstrate to Immigration that she can support herself while her, so I'm wondering if I can send an invitation letter, proof of my finances, etc., to aid her in getting the visa. And if so, for how long can she visit? And what documents should I send to whom?

Any help is greatly appreciated.

It is ok for you to send the invitation letter, but it is better for the finances to be in her account. It would look better for her case. She would be able to visit for about 6 months. The procedure usually entails an in person application to the local US embassy. I presume that would be in the capital city Lima. As for the documents they would vary from case to case, I would therefore recommend you to inform your girlfriend to book a consultation with our firm to assist her further.

If you do want further assistance then check out this website, may be able to help you with your enquiry. www.visas4america.com