Eh, I don't really think there's a need to interconnect everything in the HP series. Let's just leave Crookshanks alone and say she's just a normal half-Kneazle cat.

It's a fun theory, but since it doesn't directly impact the story, I think this is one of those things where you choose whether you believe it or not and leave it at that. Personally, I choose to believe that it's true, because now that Sirius is gone, Harry doesn't have anyone who's directly related to him besides the Dursleys; it'd be nice if he at least found his parents' cat again, even if he never realized who Crookshanks was.

(Also, I believe Crookshanks is male.)

It's a cool idea, but I don't think you should look that deep into it...

I don’t look this deep! I’ve just seen this online and thought it was cool

I liked that theory but it is a bit hard to believe. 😅

Yeah I suppose it is