hi, i have a labrador bitch called ebony(spayed)shes 4 years9 months, we have a problem with her when we tie her up,( i like to take her when i pick up the kids from school )and she isnt allowed in the play ground, so i tie her to the fence, when i leave she just barks until i get back, but when people approach her she gets agressive and lunges at them, (its people who she knows and sees regularly). ive stopped tieing her up and just wait at the side of the play ground for the kids but i know thats not addressing the problem, she is a fantastic dog in every other respect, also we have her daughter gracie who is 9 months and she has started to copy her mother,ebony did this before gracie came along . i would love to be able to take them to the shop/school and tie them up but it really puts me off.(gracie just barks she isnt agressive)ebony had a litter of pups last november and was spayed in march this year, she has calmed down a little. any advice on this would be great