Susan's had a pretty rough time even by the standards of Stephen King characters, and as she's pretty traumatised, some discussion of sensitive topics is going to come up. The most likely trigger-topics are:
- Miscarriage: Well, sort of. Susan was pregnant when she died, and the baby hasn't made it between worlds. As a result, she's dealing with having lost a child, and this is likely to come up a fair amount.
- Abuse: Over the cause of her life, Susan's been abused physically, emotionally, and sexually, and all of that's liable to colour things she says and does.
- Rape: Sexual assault, at least. Also, anyone looking into her backstory is likely to turn up a whole bunch of stuff about prostitution and underage sex of both the consensual and non-consensual kind. This probably won't come up much unless someone asks about it, though.
If any of these subjects are a problem for you, and you'd prefer me to avoid them in tagging your character(s), please comment here with what you need me to steer clear of, which character(s) of yours it affects, and preferably their username just so I'm 100% clear.