Howjado, I do understand how you feel. I can distinctly remember my daughters having it and although the first 48 hours were unpleasant we all got to grips with it and I distinctly remember not phoning my Mum up in tears.
Chickenpox varies from child to child and I do appreciate that sometimes it can be quite nasty but your daughter just needs the reassurance of you being calm on the phone. I find that I have had to learn to trust my daughter (Mum of 2) to cope when her children are poorly. We discuss symptoms and treatment...I might make the odd suggestion....but its much more about staying calm and reassuring them that they are doing the right things. If you get over emotional and panicky from a distance you will do no good whatsoever.
All of the above must go out of the window however, if things change for the worse, baby does not respond etc etc. Then you can offer more practical help.
P.S. when younger daughter had it at 18 months...we just put a very loose nappy on her, left her clothes off and let her sleep, when able to, in her cot with no blankets etc....just ensured the room was at the correct temp. Calamine lotion was used....it gets everywhere...but who cares. I've always been one to sort of 'surrender' to the illness by doing everything to make life easy for the patient and abandoning everyday procedures.