I might disregard her answer to the "i miss u" txt. That could just be her defensive mechanism deflecting the blame back to you. Somewhere deep inside her, she knows you want her back. It could be she is fighting her pride right now. There really is no guessing what is going on in her mind now.

Do you miss her more when you dont have the kids?

There is nothing wrong with you missing her. That is just your love for her that is making it hurt so much.