Bellydancing did not originate as a flirtatious dance. I have studied the history of this dance and basically it is the oldest danceform known to mankind. Every culture has aspects of it deep within it's roots... the thing is that, like most good things, it has misused in the past and the present. It has the potential to be a very worshippful dance. It is healing for the body and the emotional aspects of a woman. I personally believe that it was probably first used in praise to God.
Now in the middle east this dance has been used to pass on knowledge, woman to daughter, on the cycles of life (menstrual, pregnancy, childbirth, changes, even sexuality, spirituality, pain, loss, joy). So there are movements that mimic the processes of birth- things that can be provocative. But woman to woman this dance is a wealth of education. There is humor and instruction and security to be found, comradity... a useful tool for preserving history and finding self-expression. I would encourage any woman to participate in a group where they could be mentored to and find an outlet for discovery & expression.
Now that being said, it IS difficult to find a group of christian women to dance with. You will find that many of the girls you meet are into "pre-christian" (they will call it) religions that worship the "goddess". because historically the priestesses of Goddess temples used bellydancing as a means of temple rites. Some of these cults involved ritual sex and dancing with snakes, that sort of thing. It is an unerasable part of the dance's history. But intention is everything. Anything good can be used for evil, but that doesn't strip it of it's potential for good.
There is no better excercise that can be beneficial to a woman well into old age- it is so very healthful to the soul & it works every muscle in the body including the neck and pelvic floor, thus preventing bladder disfunction. And any woman who wants a safe and comfortable pregnancy most undoubtedly SHOULD practice it, as it strengthens all the muscles used for carrying and giving birth. You will have such an easy delivery- no joke!