She wears sleeves that are the same colour as her skin, and the abayah may fall back and uncover her arms
Question

                My wife wears hejab and wide clothes. Usually her sleeves are also wide; and because she is careful not to show anything of her body, she normally wears separate sleeves under her normal sleeves. For if she raises her arm nothing of her arm gets uncovered. The problem is these separate sleeves are of he same colour as her skin, if someone sees them he will think that what he sees are my wife’s arms, not the separate sleeves. I advised her to wear sleeves of the same colour as her garment but she refused and said she is not responsible of how the other sees her, what matters is that she is properly covered. She says that by doing this she is better than many religious women who do not care if something of their bodies is not properly covered.
Praise be to Allah.
    We have described the conditions that must be met with regard 
    to Islamically acceptable clothing in the answer to question number 6991. 
    One of these conditions is that the clothing should be thick so that it does 
    not show what is beneath it and so that the colour of the skin cannot be 
    seen. 

    If a woman wears sleeves that are similar in colour to her 
    skin, and they appear if the abaya falls back from her arms, and a person 
    who sees her thinks that this is her skin, then this is contrary to the 
    purpose for which hijab was enjoined, which is to protect women and to 
    prevent others being tempted by them. 

    Hence the opening of the sleeve should be narrow so that it 
    will not fall back and show the arm, or clothing that does not attract 
    attention should be worn underneath the abayah. 

    The aim is not only to cover the ‘awrah with any kind of 
    clothing at all; rather the aim, as well as covering, is to prevent anything 
    that attracts attention and causes fitnah. Hence women are forbidden to wear 
    tight clothes or to wear adorned clothes that attract attention, even if 
    they are covering. 

    Women are also forbidden to stamp their feet whilst walking 
    so as not to attract attention to their adornment, as Allah says 
    (interpretation of meaning):

    “And let them not stamp their feet so as to reveal what 
    they hide of their adornment”

    [al-Noor 24:31]. 

    The point is that paying attention to others is required with 
    regard to covering, and the believing woman should be a good example to 
    others and she should not put herself in a situation where she may be 
    accused, and she should not merely be content with doing better than others; 
    rather she should strive to attain perfection to the best of her ability. 

    May Allah help us all to do that which He loves and which 
    pleases Him. 

    Allah knows best.