Marle,
I am very happy that your daughter has entered rehab. I will say a prayer for you both tonight. About the sleep issue for me I'd probably say something like this.......Megan, that is so kind of you to be concerned about me. That means a lot. Thanks for showing your concern and you know what? Iam sleeping well and I hope you're sleeping better too. But that's just me. I guess I'm trying to let her know that you realize in her own way she's thinking of you no matter what guise she uses to start the conversation.
I also want to say that in the past you have sent kind words my way and they helped me over some very rough times. I wish in some way I could repay you. Just know that from one mom to another I wish you and Megan well and I will keep you both in my prayers.........you both deserve happiness........God bless.....dixied