She is a pig, her friend isn't

Good day mamas and papas in the house, please I need your help on how to go about this issue. I have been trying to explain this to my friend but they don't get me, I just joined this group but I hope I get help. The thing is I am panning to get married in 3 months time, my fiance is really good but the problem I have with her is that she is very dirty and she doesn't see the need to change. We have been dating for 9 months and you won't believe that in this 9 months, this lady has never washed my clothes, my boxers are always soaked in the toilet, the only thing she will do is bring them out and spread them like that. She would come to my house, meet dirt plates in the sink and she would leave them there and cook her indomie and get out. She has never for once cooked for me all she does is cook indomie all the time. Now, to why I am here, her best friend has accompanied her to my place twice to spend the night, she is single and searching and she is also very well behaved. The first time she came, she cleaned my entire house and my fiance sat on the bed painting nails, she even went as far as raising leg up for her to sweep underneath, no help nothing. Then later me and this girl washed my bathroom together, small time we started connecting and she cooked better ogbono soup and akpu for me. I fel in love with her straight up. When they were leaving, I gave her 20k and I gave my fiance 3k because I was just really upset with her. When the girl got home, she called me to say thank you and that she was available to help me out when next I need her to. I know she is digging me just as much as I am her as well, Ii just need advice from you all if you think it is right for me to date her and cancel my marriage plans?