This is the truth proclaimed by Sai'. But later on not finding any snake inside, she would ask for forgiveness. Like this on many occasions, she had the experience of My Divinity. Similar was the case with Kausalya and Yashoda. Though they knew that their sons were Divine, they used to get carried away by their motherly affection towards them.
Mothers are highly noble and virtuous.
Their nobility cannot be described in words. It does not matter if you do not acquire worldly wealth, but you should try to win the wealth of your mother's grace. Only then your life will be sanctified.