Samsung Galaxy S6 edge and texting issues

[AC Question]

I have a Samsung Galaxy S6 Edge. When my daughter send me a text from her iphone6, I receive it well, but if/when she sends me a pic, I get a "download" box and the pic opens on another text box like if someone else sent me a text and it says her name, Home?? Weird...Also, from time to time, when they send me a text or pic, it goes randomly to my son's phone!!
I also don't have any more sound when I receive a text...