As long as the penpal relationship was sincere and both of you did not lie too much on your real yourself then is doable
Sometimes people are afraid to escalate a "paper" relationship to a "real" one due to the risk of loosing the "actual working relationship", it's something you must evaluate carefully, are you ready to risk the current relationship for having more then that? do you think she feel the same way?
If both the answer are Yes, try to organize something in a polite and non-harrassing way, like for example go visit her country without binding it to meeting her as if she feel forced to spend her whole time with you, take a holiday there, organize a meeting with her and see what happens, if it goes well it will by itself, if it's not working you both have the chance to turn back with the knowledge that escalating the relationship to real life is a bad idea, if you are lucky you will be able to keep the current relationship even after that, otherwise, you both decided to give it a try.
My 2 cents.