The way to start making change is to seek evaluation and treatment for those in the family with ADHD. Treatment can take a little of the burden of trying to keep everyone functioning well off of you.
At the same time, make certain you are carving out time for your daughter, for just her. My daughter and I used to have one day every 2 weeks that was all about her. No one was allowed to call us or text us and we did whatever she wanted to do. It helped her feel valued and loved and gave her a reprieve from life with a sibling with ADHD.
ADDitude Community Moderator, Parenting ADHD Coach & Author, Mom to teen w/ ADHD, LDs, and autism