Text Messaging

My sister and mother came to the "big city" to do some shopping for a dress...I received a text from my sister saying they were at the mall. I texted back to see if they thought they would have time to come up and see us. She texted back it would depend on how much time they had. I wanted to know if I should run down and see them and texted back and forth to see if I should, and kept receiving the same reply.."it depends on if we are able to get all of our errands done." The texts were taking forever and I was getting frustrated (due to sleep deprivation). My wife finally said, "Why don't you just call her?!" Oh yeah...phones can do that too....