Where is all this learning coming from?

Ellaiden came in our room this past week and pointed at a sign over our bed and said "O" and "S" which were both letters in the sign. Who taught her those we wonder? We have no idea. Then a couple days ago she asked for a cracker and I held up one finger and said one cracker. She responded back with "two" then later on counted to four. Who taught her how to count we wonder? We have no idea.