Well, no surprise in my answer: I'm a guy, most all my friends have been female for some reason. And I've been pretty close with some of them; yet I havent had any friends that became more than that over time.
If a gf would have demanded I not see them anymore, I would see that as saying something about her that I would not be able to tolerate. Friends are the most important thing in the world - or one of three most important things, anyway, right alongside your family and your significant other. They're a crucial part of your support system - you cannot and should not be asked to rely 100% for everything on one person, thats just not fair, and not safe. Parting with a friend is painful; you have known them, shared much with them, for a long time, it would be unfairly heartbreaking to break 'em off just because someone demands it.
IMO, anyone who demands you to give up any friend is being mean - but hey, if there is something in particular about this one friend that really disturbs your S.O., you have to talk, come to an agreement. But if (s)he demands you to give up your friendS, plural, thats just not acceptable. Someone who wants you to give up your friends for her doesnt really love you, IMO - she wants to
have you. Thats something different.
I would tell her where to go with that and to come back when she was ready to love me for who I am, who I have become in the life I've had. You dont get born again the day you marry - you dont wipe the slate of your life and who you are clean - cause the who you are is why the other, hopefully, fell in love with you in the first place.
Anyway, I
hope I would tell her where to go with that swiftly and decidedly enough ... I would hope I wouldnt get stuck in some long, torturous thing about it.