This is personal preference. I myself prefer phone calls with certain people...just a few people actually. All others I prefer texts. For my aunt, with whom I talk regularly, we schedule our phone calls. She's close in age to me and we both really enjoy long talks to each other. For your friend who sends long texts, if your preference is for phone calls, I suggest doing your thing. Which is to keep your reply to a minimum. If your friend wants more input from you, she'll call. Maybe it helps her just to vent(?). On that note, I wonder if she has considered just journaling when she needs to vent.
BBC have reported the following about Reform!

