Hi!

Tough situation!  I know you love your daughter very much and only want the best for her, but she is 21 and is an adult, she will need to be responsible for her own decisions and she will benefit or suffer the outcome of those decisions.  You can talk to her, guide her and help her think through her actions.  You can be there for her, continue to show love but you don't have to agree with her choices or support them.

As far as the clean room goes, she is 21, if she has been allowed to not be responsible for her room through all these years, you can give it up, she's not going to suddenly begin to respect her room.  On the bright side, when she moves away from home, as she will probably do soon, she will most likely take responsibility for a clean home.  I had friends who never picked up at their parents or cleaned their room, but they keep very nice homes.  When in joking a comment is made they simply reply "that was Mom & Dad's house, this is my house"  and that is the way a lot of kids feel especially if they had not been given the responsibility.  I guess they just feel that it's the parent's responsibility to do it for them and in turn they will keep a clean home for themselves and their kids.  It's one of those things that seem to pass from one generation to the next unless someone changes the "rules".  

You mention "toxic Mother" when referring to your parent, which indicates to me that you may have had a similar situation with your own parents, comes back to passing from one generation to another.  Grandparents do tend to spoil their precious grandchildren, but ages 21 and 17 is not the time to address it.  Just accept the relationships for what they are, resolve any issues you may have of your own feelings with your parents, children and let the past be just that "the past".  Focus on "today" and live in that time "real time" and move forward from here.

Best wishes!