Can you take lexapro and diazepam the same day?

Hi one and all, my cousin who is in her sixties has been taking Seroxat and Diazepam as prescribed by her doctor and has been doing so for a few years now as she suffers from PTSD however I don't think Seroxat is suitable for a lot of people (including myself). I was the lucky one, I refused to take the drug and slowly came off it and went onto another SSRI type drug and then I built up the courage to go cold turkey as I really did not feel any better by taking either of these. However I did take a lot of drugs in my youth and felt that I could handle the nightmares that followed and I did! I think sometimes you have to take drastic action to get the result you crave although I am not fully cured of my particular PTSD I feel a lot better knowing that I do not have to take these drugs again. So to recap my cousin seems to be ok on both of these but I personally don't think it's the be all and end all cure for any depression or PTSD problems a lot of us seem to have.