when we were training ours, we would put her on the harness and leash and have my children, (from ages 7-15) gently walk her around the kitchen and also reinforce her commands (like sit) and give her a small treat. She seemed to respect that and enjoy it.
I have heard it is not uncommon though for some yorkies to not love being with all small children, so it might just take time and patience. The yorkie rescue in our area doesn't like to let families with children under 8 adopt.
I think you have received much good advice and this is just something that worked for us
