Hmm.. well, did anda try the Polyjuice potion yet? If anda did, then anda might be able to get into the common room oleh going through the chapter, like anda always do.. (I haven't been on pottermore in forever so sorry if I get stuff wrong) If anda can't do that, then maybe , try and add somebody that's a Slytherin and see if anda can get in then. =/