This is such a rude comment to make. If you said that for you yourself wouldn’t marry a divorced or widowed person it is understandable because that is your preference, but by generalising and saying no divorced person should ever marry a single person who has never been married is outright mean and wrong. This shows you have a very narrow way of thinking. There is person who has commented that she got divorced before the rukhsati, and she has never experienced a proper marriage where she lived with her husband, she should get the chance again, so should other divorcees. The most important thing when marrying someone is finding compatibility and that you will be able to love each other forever. Of course you have the right to say no to someone that is divorced or widowed but doesn’t mean they shouldn’t marry someone they like.
To the OP, this is a big decision marrying this girl not because she is divorced but because your parents don’t like her, they will make her life hell and would you be willing to protect her and not just for the first few months or years but life. If you can’t commit to her and give her share of happiness properly there is no point ruining the girls life where she may end up with another divorce. You say now you love her but once you parents start putting pressure, will you still support her? If you were to separate from your parents, would you not miss your parents and feel guilty and later take it out on her. Also are you willing to treat her daughter like your own?