hi, sorry to hear about your daugher. i too met some good friends in meetings. i'm a recovering addict but it was my ah that brought me to this site. according to what you've posted, i'm sorry to say that to me it kind of sounds like your daugher may not be quite ready to quit. i pray that i''m wrong thought.
you have nothing to feel guilty about, none of this is your fault. maybe its time for you to focus more on you. your daughter is gonna do just what she choose to do until she is ready to stop. going to your sisters sounds like a good idea. maybe you could try going to a few extra alanon or naranon meetings for yourself. keep reading and posting, others will be along shortly with more support.
for me, it took for my family to take a step back and allow me to hit rock bottom, then and only then was i ready to get serious about recovery. in my opinion, you may be helping your daughter more by not allowing her to continue to take you down with her. i pray that she finds her way soon and i pray that your hp give you strength to let go and let god.