All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
If this woman is as you have stated and has these good qualities, in addition to being brought up by pious parents, then we advise you to marry her as the criteria for marriage is religion and good moral conduct. The Prophet said: "…so marry the religious one…" [Al-Bukhari and Muslim] However, before marriage you should make Istikhaara prayer and ask Allaah, as He is the Knower of the unseen. You have also to seek the advice of the people who know her and know her family. As regards the thoughts that you have stated, you should not take them into consideration for many reasons:
Firstly, even if a woman is a fornicator then she repents, what she committed before that should not be taken into account. So what about this woman who is not known to have committed something like that? In principle a Muslim is innocent and we should not be suspicious about her except with clear evidence. As regards Hijab, you have stated that she is prepared to wear it, and she showed some signs of covering herself properly.
Secondly, virginity could be lost without sexual intercourse, like a sudden jump and so on. So one should not seek to find out the reason why the woman is not virgin. It is also not permissible to make her undergo a medical examination to discover whether or not she is virgin, as this requires looking at the private parts.
What you can do is set a condition to her guardian in the contract, and after the marriage is consummated you discover that she is not a virgin because of sexual intercourse, then you can cancel the contract if you do not express agreement to it. However, if it is proven that her virginity is lost because of other reasons than sexual intercourse, then you do not have a choice to cancel the contract according to the most preponderant opinion of the scholars. However, if you choose to invalidate the contract, it is permissible for you to take back the dowry because you were cheated by the guardian or his representative, or by the wife. Anyway, we think that you should not invalidate the contract as long as the woman is pleasing regarding her religion and moral conduct.
Thirdly, it is very rare to find a woman with perfect qualities, as the Prophet said: "A male believer should not hate a female believer; if he dislikes one quality in herself, he would like another quality in her." [Muslim] It could be that if you marry her you would discover many good qualities in her, and you might marry another woman for her virginity and you will discover some bad qualities that would embitter you to her.
Allaah knows best.