A recent study prove that video games can be beneficial and most kids use their devices to socialize. So if they are happy and you are benefiting, then what is the problem, that you are not meeting a perceived notion of what the world thinks is good parenting? I say phooey let your family's happiness and health be your guide that is what is a good mother.
My t put it this way: are they safe, are they sheltered, do they have food and do they perceive love? If the answer is yes, then you are a good mom.