I have had a really difficult time with my DH's two daughters. Both have lived with us (the 22 year is here now) on the pretense of going to college, but neither ended up making it. I continue to worry about the example SD sets for my 15 year old, but lately it is having a curious and unintended benefit: rather than admiring and trying to emulate here, my son has seen the effects of not succeeding in university; being stuck in dead end jobs and having to live in your parents basement; not having money to travel, do and experience the benefits of maturity the way his 4 adult cousins (on my side) who have all grown up to be successful professionals. So I understand your fears but trust in your own parenting and the values you have instilled in your children. At 11 and 14, those values will be well rooted by now in your children and your SD will not be able to change that. Word of warning: if SD ends up at your place, insist on ground rules and a contract BEFORE she moves in -- not with her, but your husband. My experience is that it is the dads who are the root of the problem and the stepmoms end up living with the effects of lifelong lack of discipline/low expectations/zero accountability, all made worse by divorce guilt!