Charley...

✡Bracha✡♈ • Mom of David 14months&Esther1 month
So my 13 year old sister has this friend who was born a girl into a religious orthodox jewish family and had a hebrew name but now has come out as a boy and says her name is charley and that shes a boy. Alot of parents have stopped letting her over to play with their daughters but my mom still lets my mom is more modern than some of her friends. Anyways i feel bad for her tbh because shes had to leave the school she lost like all her friends and now everybody just thinks shes strange aside from my sister and mom etc. My question is this what would you advise this girl to do? I ask because i am very open with my little sister and her friends and i remember like a year ago before all of this started i discussed sexuality with them as they brought it up and asked me (im 24 and married with kids).. since no one else would discuss it with them ( no sex ed in orthodox schools) and i remember she said something that made me think that perhaps she was struggling with the topic. Anyways she comes over alot and tbh i have zero knowledge about anything transgender or anything lgbt either. She tries to talk to me but i have no idea what to say. I have nothing against her.. what do i do? Without being awkward. I really just dont know what to say im surprised and know nothing about the community but dont want her to feel as if i dont care about her.. suggestions welcome thanks.