There should never be exceptions to God's word.
I believe that there is some grey areas in scripture that require individuals to make conscience based decisions--but many things, like how to worship God or how to live out our lives for Him are black and white.
God planned a role for the husband and for the wife. He doesn't want us to take the easy way out, He wants us to grow through the challenges.
God has not commanded that all women will stay at home, care for it and the children no matter what.
Scripture does not teach that a woman cannot have a career, nor does it teach that a man must.
So if God has given you the gift, and desire, to be a homemaker, it's best for your situation and will lead to fulfilment, then go for it. How will it benefit you to struggle on in a job you hate while longing to be at home? If you think you can force yourself to carry on and deal with the frustration and your heart not being in what you do; go ahead. But I'm sure it would be best for you, your boss (if your heart isn't in your work) and your family if you were able to do what God has given you a passion for doing.
Is your sister a Christian? She should be listening to what God says, and not guided by emotions or personal preferences.
Perhaps she is.
God has given us the capability to change our internal desires and how we perceive the world...
How do you know it wasn't God who gave those desires in the first place?
Scripture says that if we delight ourselves in the Lord he will give us the desires of our hearts, Psalm 37:4. It's not wrong to have desires - and if we belong to the Lord and have given our lives to him, then our desires are his as well. This is what the Psalmist means; be in the Lord, delight yourself in him, delight to know and serve him, then he will give you the desires that are in your heart. So even if you believe that your desires are just your own, and own feelings, if you belong to the Lord and give your desires to him, you may find that he allows you to fulfil them.
..He makes it possible to enjoy things we didn't think we could.
But that doesn't mean that he commanded, and willed, for us to do them in the first place.
He makes it possible (because He expects it) to rejoice always!
But if someone is in a role that God has not put them in and is not right for them, should they rejoice, or should they get out and find what his will is?
Paul teaches that with "food and covering we are to be CONTENT" (1 Tim. 6:8). So if your sister in that situation, or me in my situation are whining and complaining and not letting God mold us--that's a problem!
If you are in a role that is not right for you and contrary to your God given gifts, then it could well be that your dissatisfaction and unease is from God. He might be saying "get out and do what I created you to do; what you were made for".
God designed/created men to lead and women to be nurturing child-bearers...it's possible for EVERYONE to fulfill their role to God--
Yet some men can't lead and some women can't, and will never have, children. Some women choose not to have children, even choose to remain single. Some women have a God given career and children.
God's word shall never be compromised, unless He has authorized such a compromise.
God's word does not command all women to stay at home, keep house and look after the children.