It’s nobody’s fault. But it is her job as a parent to accept it. The things she payed for to support you are not a burden she can guilt you with. Some parents have kids who never get to walk or talk, if they never let go of the disappointment for “what could’ve been” it does nothing but hurt the child. Does your mom consider that your stutter impacts you the most and not her? Does she consider that you can be happy despite your circumstances? I don’t know if you can tell but I have zero sympathy for your mom rn