In my teenage years, I was also one of those OTD teenagers. Firstly having the most amazing people take me in under their wing that was a life savior for me. ( No I was not some junkie off the street)
“Tatty” was always calm about the situation whatever it was. Never bashed me for doing x,y,z. Instead well I knew he disapproved.. but always showed me love, & was understanding Never forced me anything.
“Mommy” pretty much the same- she would sometimes make comments bout tzniut or sm things like that.. yes as a teenager it annoyed me to some degree. but I am thankful now. ( I still get those comments here and there today! thats just the was she is)
Also My Boyfriend at the time same thing. – and those who pick out at every word and make an issue out of it.. no, im not saying oh so let them find a boy/ girl friend.
My point is I agree with many of the comments above that you need to show unconditional love, show them the beauty of Judaism- don’t get up in their face. They are more likely to return