The first thing is that you have to take a clear stand on this, and do not give in to her. Tell here that while you are quite prepared to do your share of the household chores, you expect her to do the same.
Secondly, make sure that she understands what standards of behavior are acceptable, and which are not. This might include no denigrating remarks and honesty and responsibility.
People with her personality are rather liable to push things to see what happens, and what they really need are firm boundaries. Being ‘soft’ and trying to please them just makes you easier to manipulate
She is quite old enough to know about actions and consequences. We humans only indulge in behaviour that brings reward of some kind. Only when that reward (whatever it might be) disappears, or the consequences of our behaviour promise to be unpleasant do we consider changing what we do. Therefore, make her behaviour unrewarding to her.
Here is the clue to sorting things out. When you are faced with non-co-operation – give her choices, and make sure she understands the consequences of her choice – and always follow through. If you don’t she’ll just get confused
Make it clear what you expect - "If you continue to call me retard, or otherwise insult me, I shall simply walk away and ignore you until you can be more civil and adult. I am not prepared to be insulted in the way you have gotten away with in the past.”
Never get angry, stay cool and in control, matter of fact and stick to the facts. Avoid drama.
Never, never be blaming or accusatory. Tell her how you feel about her behaviour, and make sure she understands that while you love her, her bad behaviour is hurtful and will not be accepted.
Remember, you do not exist to please her, or meet her needs. It cannot be all one-way traffic
This Bill of Rights was one of the tools used by Virginia Satir, a well-known family therapist. Containing some really basic psychological rights belonging to every person, it really helps to identify and deal with areas in which we have problems.
Read the statements. Note down any immediate thoughts or feelings that come to you.
Look at yourself in a mirror and read it out loud to yourself. Listen to your voice grow in strength and volume so that you can really start to feel it inside. In the beginning, you may feel silly or embarrassed. You may hear the inner voice say, "That's not the truth". Just hang in there and keep doing it - you'll notice the change within six weeks, if you do it regularly.
1. I do not have to feel guilty just because someone else does not like what I do, say, think or feel.
2. It is O. K. for me to feel angry and to express it in responsible ways.
3. I do not have to assume full responsibility for making decisions, particularly where others share responsibility for making the decisions.
4. I have the right to say "I don't understand" without feeling stupid or guilty.
5. I have the right to say NO.
6. I have the right to say No without feeling guilty.
7. I do not have to apologise or give reasons when I say NO.
8. I have the right to refuse requests which others make of me.
9. I have the right to tell others when I think they are manipulating, conning, or treating me unfairly.
10. I have the right to refuse additional responsibilities without feeling guilty.
11. I have a right to tell others when their behaviour annoys me.
12. I do not have to compromise my personal integrity.
13. I have a right to make mistakes and be responsible for them. I have a right to be wrong.
14. I do not have to be liked, admired, or respected by everyone for everything I do.
Best wishes, NormanM