#Rouge mentions having a mother in some racing quote in TSR if I'm not mistaken but that is about all mentions of parents we get

[true-blue-sonic]

While I think a lot of Sonic characters are orphans, Silver in particular has likely had to watch whatever friends and family he had die in front of him at some point.

I myself also always got the feeling Silver got abandoned or otherwise lost any caretakers he had at a young age, due to his relative lack of social skills in both Rivals games (Rivals 1 more than 2, but even in 2 he does not lack the occasional rudeness, lol) and the fact that he just seems to be travelling to the past alone with no support or back-up from the future. But I doubt we'll ever find that out for sure, since Sonic is a franchise where there's legit just one (1) parent present and all the teens and young adults just do whatever, haha. In that regard, Silver doesn't stand out too much! Whether or not his caretakers actually died/died in front of him I cannot say with certainty, but that is a question Sonic leaves unanswered for basically all its characters anyway. But you can bet that Sonic and co happily adopt Silver right into the friend group, and Vanilla is keeping an eye on the sidelines at everyone as well. So he'll be looked after well in the past for sure! <3