I have a friend who is coming to the US to stay with me for 3 months. I'd like to get her a US phone while she's here so she doesn't have to pay extra text charges. i've never done something like this before so I'm not sure where to start or what the best option is. I've heard of buying an old iphone (what I have now), getting a sim card (no idea what that means or what a sim card is), or getting a prepaid phone with x minutes/text messages on it. Not sure where to start with those but wondering what would be the best option - it would be for texting ONLY (friend is deaf).