In order to be able correlate more accurate your wife need to check liver status by Fibroscan or biopsy (if Fibroscan is not available in you area) and also HBsAg quantitative if is possible and also. (for HBsAg quantitative result have to be in UI/ml and not in COI (COI is a reactive level and not a quantitative))
HBV DNA is 231 - UI/ml or cop/ml ? - anyway this is a low value.
"According to these test result what is the condition right now. " - It looks to me to be in a non active phase, but for this one you need the indicated tests.
"Could HbeAg turn into Positive in the future?" - yes, even if is with a low probability. In theory and some times also in practice the Ag HBe can become positive again, but this in not a common way.
"What kind of treatment does she need?" - this has to be answer by a good doctor and basically the answer has to be based on the Fibroscan results corelated to other blood results.
"Can HbsAg turn into Negative?" - yes, but with a low probability. Actual rate is 1 - 2 % per year without medication. with medication (especial a combo) this can increase but nut to much (also depends on the body response, time of treatment - but it will go around 10% or something). For future it seams that new treatments are on the horizon: like rep9ac or Myrcludex-B,for this keep an eye on http://www.medhelp.org/posts/Hepatitis-B/Entry-inhibitors-show-promise-as-drugs/show/1570784?page=1
"If yes after HbsAg negative, can she get Hepatitis B virus spread inside her body? I heard some people say after HbsAg negative, she can get Hepatitis B vaccination?" - after HbsAg negative is possible that the body will develop the antibody and in this case is not need for a new vaccine. after HbsAg negative you should check anti HbsAc level and base on that level (cut off value is 10 UI/ml if I remember correct) is decide if a vaccine is needed of not.
"Can she have sex during hepatitis B +?" - yes, use a condom if you are not vaccinated (and get a vaccine asap ) or if you are vaccine and immune (see anti HbsAc level) sexual life has to be normal (like it was until now)
"Can sex can make her Hepatitis B more worst?" - No, this are 2 separate things and are not related.