What kind of phone does she have? Also, when she's texting you, is she using smileys that are installed on that phone as well (similar to our emoji's on the iPhone)
Reason I ask is because 2wks ago, both my parents have the lg octane and it comes with it's own smileys installed on the ph. When they were txing me using them I was getting all sorts of symbols for the msg. We realized within minutes that was the problem and wen they just make their own smileys now like this : ) etc. Msgs are fine.
We've also discovered that I can't use the iPhones installed emojis to them either as they wind up with a text msg full of square boxes !! Lol.