<human>: Condense the text into a few key points

Hey, r/relationships. *First, sorry for any grammatical errors, and if I'm not too in depth about my financial situation, it's because I don't want to give many details, and because English isn't my first language.*

So, as the title says, my mother and her family don't like my girlfriend [F24] because she is 3 years older than me, and they come from families where the man is older than the woman, so it should be the same for me. My dad doesn't care about the age gap, he's friends with her dad and they're cool with me and my girlfriend being together.

That's literally the only thing they dislike about our relationship. She is smart, beautiful, funny, lovely, her family is lovely, she will have a very good income once she finds a job (and I'll do too, I'm not a golddigger) plus we have a lot in common. And it's a serious relationship (together for 4 years, and we've been friends even before that for like, another 5 years), we're considering marriage once we both finish college and when we'll both be stable financially).

I don't depend on my parents' money, I worked lots of part time jobs since I was 16, so I have some savings, and I'll be able to pay my college tuition when I'll get a job (as I said, I'll be able to easily sustain a family, and she can too, so we won't be poor), that being said, I could easily cut contact with them, but they're family..

What should I do? If nothing succeeds, I guess I'll have to cut contact, won't I?
<bot>: My mother and her family don't approve the relationship I have with a girl who is 3 years older than me. What should I do?