Here is my question -- did she ever tell dad that she moved the child to VA? And is dad paying child support that is court ordered? Because I lost that fact in this mess.
OP has stated that Dad is in no way the legal father. She would therefore have no obligation to notify Dad she moved to VA and since the move to VA was over 2 years ago, it would be a little late now for Dad to claim an objection to the move.
But, OP, you do need to answer the question above.:
--> is dad paying child support that is court ordered?
And, to expand that, has there ever been an order for dad to pay child support for this child, whether he paid it ever or is currently paying it?
Also, did Dad have contact with the child when she lived in CA previously?
Has Dad had contact with the child since she's been staying with your mother in CA recently?
Also for residency, the 3 month county requirement goes along with the state 6 mo requirement. IF you are both parties of the state for 6 months THEN if you are a resident of a particular CA county for 3 months, THEN you can file in THAT county (vs. another CA county).
I disagree the other state is an inconvenient forum since clearly Mom lives there, it's only where the child lives that's in question and child has not child established residency in CA because she's not been there 6 mo yet.