She doesn't think she's made any mistake with respect to the dog or anything else.

When my other sister called her to pass on that my bf had taken a turn for the worst, she felt obligated to respond in some way. She could have called me, but she preferred to send a text message. She is minimizing her interaction with me. This has been going on for 15 years. It's not a normal way to treat a sister. I have made phone calls after months of not hearing from her. I have traveled to visit her. I'm not going to keep telephoning someone who seems to want to avoid talking with me on the telephone. I would feel pushy doing that.