ANSWER:

You must not accompany them in public as this would be endorsing their sin and accepting it. 

QUESTION: Sheikh sometimes my family go outside, to restaurants etc. I want to go with them and enjoy family time. But the women of my family dont abide by the hijab and wear makeup and perfume.im the youngest in my family and hence my advice would not have any importance and instead would cause a fight. If i go with them, would i be considered a dayyouth and sinful?