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 have already clarified in Fatwa 90797 the criteria for choosing a wife in Islam, the most important of which is her religion as highlighted by the Prophet . In addition to this, if she is virgin and she is from an honourable and descent family lineage and so forth, then this is even better.
However, if a woman is religious and has a good moral conduct, then the parents of the man (who wants to propose to her) should not refuse her just because she is divorced and the like, or because of her being older than him; for more benefit, please refer to Fatwa 83142.
Therefore, we advise you to try to convince your parents to accept your marriage to her. First of all, you should seek the help of Allaah, and then the help of whomever can influence them. If they are convinced, then this is what is required, otherwise you are obliged to obey them because it is an obligation to obey the parents whereas you are not obliged to marry this specific woman. Moreover, it might be that your parents are more informed about her and that they are more experienced in life, so they know better. So, if you obey them, you may achieve marital happiness.
Allaah Knows best.