Hello GrandmaM

We are pleased you found this site too and I do think this forum for parents will be a good place for you to read and post as you are in a sort of parental role with your grandchild.
How old is she now?
One of the features of BPD is confusion about identity and this must be doubly difficult where there are gender identity issues.
Please post again and tell us a bit more about the problems you are facing. In the meantime there are links to helpful articles which you can read.