With respect to mango juice, I wouldn't go anywhere near citolopram. It's excellent for some anxious or depressed people, but has side effects like any other drug of its kind - including insomnia!! That's the last thing your friend wants.
The herbal suggestions seem best, with camomile tea and oil of evening primrose being probably two of the more gentle relaxants.
Black cohosh has been discovered to have side effects as well - notably stomach complaints and headaches, in some people. There've also been reports of it causing liver damage, although this hasn't been substantiated. However, mixtures containing black cohosh sometimes give warnings that it shouldn't be given to people with liver complaints, so it's best to err on the side of caution.
Another tip for your friend, snt79, is that she might like to try relaxation tapes. These've helped friends of mine. x