My girlfriend always struggles to make female friends, women seem to make snide comments have you experienced this?

I've always found this to be quite odd, she's is absolutely gorgeous in my eyes but very shy.

She's kind and struggles with her confidence but pushes on anyways.

I always tell her she is probably the nicest person I've ever met.

As a consequence she doesn't always see when someone doesn't have her best interest at heart.

My only criticism is when she feels slighted she can be defensive and doesn't address the issue head on.