My good good friend is BPD (so am I) and we are both part of a larger friend group, though she and I are closer with one another than we are with anyone else in the group.

This really friend hates to be excluded or to fell ganged up on/isolated.  She also feels that of the two of us, I am the better liked within the group. She often interprets things that people say or actions that would be viewed as inconsequential to most as her being attacked or people showing hostility. She also feels hurt if people pay particular attention to me. And at times there has been genuine hostility from a single member of the group towards her, however this person is just very hostile to everyone (we're trying to work with them) so I don't believe that this indicates a specific dislike of her, though I still understand that it's hurtful either way because they're still being rude and mean. All of this will upset her deeply. Sometimes she'll get upset and leave our group chat for days at a time to even a week or so after feeling she's been attacked, believing that nobody cares or she is unneeded though in reality we all love her very much. She'll also come to me angry, voicing her greivances seeming like she wants some response from me - but I feel like my reassurances don't help at all most of the time and I don't know how to just passively listen without sounding like I don't care. These are issues  like "Why do they feel the need to kiss your ass so often" or "I hate how I get ganged up on for anything I say to you" so obviously questions that are difficult to respond to without making things worse.

So how do I reassure my friend that she's liked, wanted, that I won't abandon her or that we aren't losing interest? She's been going through a difficult time and this definitely isn't helping. How do I answer her when she comes to me with questions where I feel like I'm damned if I do or if I don't? How do I make her feel more welcome without outting her feelings to the whole group that may be less than understanding?  