Ok, this is what I did with my niece, who was a similar age at the time...
It was with our mini Schnauzer (Sam), so slightly larger. Firstly, I didn't keep him away from us all - but I DID keep him on his lead. Then I was in control of who did what, and when.
I made Sam sit next to me, and gave my niece some doggy treats. I told her she didn't have to give them, it was up to her.
We all then carried on with our day as if there was nothing different and nothing 'in the air', but kept Sam, on the lead, next to me at all times.
It didn't happen quickly, but I realised she was rolling some of the treats gently towards him. She jumped and ran away a few times, as Sam reached for them. I think it was the speed, and the little sticky-out tongue....but each time she visited it got gradually better and better. Softly, softly...
May I add, it ended up that they were THE best friends, and used to curl up in Sam's bed together....
Good luck! Sally + Harry x