My parents don't like my gf =ultimatum

I have been dating this amazing woman for 2 years now and she has been very good to me. Around the 4 month mark everything was going well when my mom and my gf and I were having a joking conversation about moving out when my gf said "well maybe is it you don't want him to move out because he is your baby or because he does a lot for you guys around the house" which in Hispanic culture and form of opionation or talk back is regarded as offensive and disrespectful. My gf is white so there is a culture upbringing and understanding difference obviously. We all had a talk and cleared the air and to an outsider as my gf came across as a tad confrontive. All was washed and after that my gf was unsure where she stood and after already being shy she was hesitant to see my parents if fear of them being mad at her. After a few months my parents quizzed me on why she didn't come around as much and why she didn't say hi on a few occasions. As I partially realized this and asked my gf she told me she was slightly scared and nervous and felt hesitant and she didn't know how to approach my parents. Another misunderstanding took place between her and my little brother which caused all hell to break loose and she was banned from my house and I was given an ultimatum to either choose my "disrespectful bad apple gf" or leave her and stay in the house. I concluded that there was no way I could choose between them because I see how my parents saw this and couldn't persuade them to see it how I saw it nor how my gf felt or meant by the situation. Eventually we all talked it out and slate was clean... All was good for awhile and my gf and I got busier, she mostly was able to spend time with my bros but not as much my parents. A cultural diff occurs here, apparently in Hispanic culture my parents should be expecting my gf to come around way more and try to be friend with my mother for the first event and become ore like my family. Of course once again I have been given the ultimatum to choose my gf over my family because she doesn't come around as much as well as they think her to be a bad apple. My gf and I were doing awesome and have gotten very close, and thought all was well with my parents. She is an awesome girl in my eyes and I love her so much. I am lost as to what to do... I think a cultural divide is occurring here where my gf being raised differently and my parents expectations are far apart but I don't think she's a bad girl nor am I that blind to miss the facts. Help!?