Is my 10 month old daughter advanced?

My 9 year old son walked at 8 months old so he seemed a little fast with his cognitive skills. But my now 10 month old daughter started walking at 9 months talking at 9 months (sign language at 6 months). We speak eng. and she will repeat Dora when my kids watch it. This morning I woke up and I swear she was repeating three consecutve words over and over again. Off two different shows I had playing in the background (we usually don't let her watch t.v.). Then when a show came on and this girl was hiccuping she looked at me started hiccuping and laughed then did it once more. I am starting to get scared.