Common assault what is the likely sentence? it happend in the a domestic context.?

i was charged with s39 common assault. my partner will not press charge but police have picture of bruises. however i admitted it very early at the police station. i have been to magistrate court last friday and the judge refers me to probation officer for a presenting report. this is my first offence. my 4 year child was present in the house at the time but did not actually see the act as he was downstairs in the bedroom. i believe my partner will not press charge and she did not come to court on friday.the prosecutor mention the fact that i used my belt a couple of times on my partner. but she did not mention the fact that she also hit me with a computeur cable.i was order not to contact her but she is texting me to tell me that she did not want our relationship to end. i love her too and i want my relationship with her to continue. what is the likely sentence for this? i'm working full time and studying full time aswell. never get into a trouble before.please help me.