Just bought a arab, how to stop my arab from spooking ect.. general questionns?

my 15hh arab is a lovely girl (had her a month) but just will not go near water, if were out hacking it takes at least 20minutes to get her past it even if its just a puddle, she wont buck or bomb she just backs up and panics, she is a real fairy! and just wondering how to stop her from spooking so much like in the school we have bushes down on side and soon as some wind comes she leaps to the side and is wary of going past again although she will go past she will be jumpy, also just before or after canter she holds her head high which i can understand due to her been a arab but whats the best way to get her to lower it without a martingale? when getting on her she will not stay still even if someone hold her you have to get on while shes moving, all of these things i can cope with and its not a huge worry im just wondering if there's any tips or tricks to stop her being such a puff!