The move to secondary school shakes some long established groups. Keep an eye on it. Check out any new members. Be wary if your students group breaks up. Do what you can to help establish new connections.
Loners are vulnerable and without support in a new and scary environment.
Connected Stay Connected Information is your best tool in helping your child be successful. Go to the parent evenings. Introduce yourself to teachers. Introduce yourself to consellors. If your student has a special ed.