Welcome to SR......I'm glad you found us but am very sorry that your dear daughter is dealing with the challenge of recovering from addiction.
I hope you are prepared to get some pretty honest answers here. There are many of us who have been dealing with addicted adult offspring for a very long time. We know the ropes and there are some red flags in your post that I suspect are going to be pointed out.
You've moved out of your own home? Because she can't be respectful, polite, and grateful? That sounds like enabling to me.
She (or you) doesn't want relatives to know about her addiction? Covering it up....that could be considered enabling.
She wants you to make excuses and do the "white lie" thing for her? Yup......that also sounds like enabling.
Are you making a mountain out of a mole hill? No. It's all of these little (except the house thing.....that's a doozie) things that make it easier for the addict (or recovering addict) to use. We (the codependent parents) aren't responsible for their addiction but we sure make it easy for them to continue.
If we can't say "No" to the little stuff......how can we say no to the stuff that's really important?
Never do for the addict what they can and should do for themselves.
I know this is tough......but catering to her in recovery is no different than catering to her in her disease.
gentle hugs
ke