Two of my grandchildren are like this, they are 8 and 12. My son is a single father, who had a huge horrible break-up 5 years ago with his partner who left him and the children for another man. The two GC have heard everything and seen everything that has happened, including endless fights and nastiness. Plus the fact that their mother left them when they were 3 and 7 because they were "too much trouble". My son is very relaxed about rules, kids making choices, etc so they basically make their own decisions about everything. Unsuitable clothes are the least of my worries ! And funnily enough, they are both the most happy, well-behaved children , with impeccable manners and balanced views on life. So don't despair, things will probably work out for the best and even if they don't, all we can do as grandparents is to watch and support them. Best wishes to you .