It all depends on how much you like/love her.
You shouldn't blame her for her past histories, everyone out
there has their own good and bad histories. The reason why you
shouldn't blame her for her past is because you weren't in her past
to convince her what she's doing is wrong. And if you didn't exist
in her past, then you certainly do not have any rights to bring it
up and neither should they become your concerns.
And you shouldn't allow yourself to be troubled with her reply
if both of you were to break up in the future. That's because she
won't have anything else to do with you once she's broken up with
you and you won't have anything else to do with her if you have
broken up with her. It's called severing ties when a
relationship is broken up. Most of the time, the relationship ties
doesn't sever off completely due to past attachments or habits or
life routine. You just need to cut off the remaining relationship
ties yourself.
You can only FORGIVE her past and NEVER FORGET. I'm sure that's
what she is going through as well, and carrying them as an
emotional burden which she will NEVER be able to erase it from her
stained soul.
But if you really do love her, please do not allow her past to
affect your relationship negatively. Instead, use her past to
treasure, love and cherish her for who she is and ALWAYS
look forward to the present and the future...so that your
relationship will keep growing and eventually blossom. I know
this kind of past will affect most if not all guys in a
relationship with her, but you can become the outstanding guy among
the rest of the other plain and ordinary guys out there in your
society.
Not really sure if this will make you feel better, but at least
you had a girlfriend who was wanted by at least 30 guys in the
past. Isn't it better than having a girlfriend who was
shunned/avoided by all guys in the past?
If you want to marry her, then you should keep and nurture this
relationship together with her. But if you mind, then you
should let her go so that she can find other guys who will
be more kind to her than you.
And don't count the score and her histories, cos ultimately it
all comes down to how much you want her to be in your future and do
you really have true love for her.
Don't do inhumane things to your girlfriend or I will curse your
ku ku until it rots and melt into dirty water the next morning when
you wakes up. 
i like this =)
treat her with grace, accepting her regardless of her past.
