(in this au Tom was originally married to a different lady before Maddie, so your Tom's kid from that marriage)
you were 10 when she died. Your real mom. 11 when Tom re-married a lady named Maddie, she's nice, but you hate her. Why? Because she replaced your mom in your eyes. And then a week later this...blue looking hedgehog came along into your life...his name is Sonic, he's so...loud..but he's nice...
after some time you got closer to sonic, talked to him about your mom, how you missed her. He understood he listened, you guys did everything together...(like all the stuff shadow did with Maria as an example)
now you're 16 and holy fuck your life had changed so much. Tails and knuckles showed up a year after Sonic, and now you hardly leave your room. Why? You're depressed...mostly from school and all the "dead mom" jokes your bullys pull. And from just life itself. and it's been really showing more and more every day, and sonic hates it! Because lets be for real...you were his maria (you and sonic are close like how shadow and Maria were)