年龄的常识问题

年龄的常识问题
my English teacher don't tell us how old is she,but she is more than forty years old.And她属牛,She就是40多岁,不超过fifty.
please every past手 ,tell me,how old is she?
不能乱猜,要根据她属牛和12个生肖（即12年）为一转.来算!
thanks a lot!If you answer well,i will add 10-20 points more.
哎呀，说错了，是猴，打错字了。
你个吗b招展，好串，分就偏不给你，吹呀！