S.W.
You may need to have it professional exterminted again for the fleas. When we bought our current home it had lots fleas and it took about 3 treaments before they were gone. We tried home treatments but they just did not work. Let them know you have a child, we usually had our house treated when we were going away for the week-end, so that we did not have to be there when it was the strongest. It always worked for us.
NOTE: After you vacumn the house throw away the bag because the eggs can hatch in there, and there you go again with the fleas. And if you have a bagless system check your filter and clean it with a toothbrush to make sure the eggs are not there as well.
Good Luck.