Possessive child

My daughter is 2.7 yrs old. When she was 8 months, i resumed my job and i continued till she was 1.8yrs old, so naturally she became used to it. My absence never bothered her and she was very managable by the aged members of my family. But after that due to some inevitable circumstances, i had to leave my job. So since a year i am at home, and we become so attached that now she is insecure and possessive. She doesn't cares anybody on earth. She is now admitted in a play school, where i am too associated. In the school she behaves abnormally quiet and shy. She never speaks, but she is very obstinate. She never obeys her teachers, neither follows her friends. Rather deliberately does the thing she is not asked to do. She catches the bad habbits of other pupils too fast. She immitates all the activities in the school and repeats it in the home. She is too intelligent and can pick up any thing in no time without repeat. But destructive in nature and tends to go negative. She bites, hits, kicks, spits and becomes messy when stopped to let go her decisions. She shouts and complains to any unknown person she comes across. If we share anything with her and her friends she never takes her share neither she allows any one to take thier own share! But the only one who can keep her under control is me. I have to hug her tight till she calms down and then change her concentration to other thngs. But that is not always possible as this is a joint family and i have all the aged people here, so naturally she is too pampered. She knows this fact so acts very smartly to avoid me. Please suggest a way out as i feel these habbits will take her to a wrong way and when she grows up this immature acts will make her life difficult.Please help!!