Can آپ give your spots to someone else?

I don't think that's possible, seeing as no one really owns the spot. Not even the one who created it, and that person doesn't have a higher "status" than other شائقین of the spot either. There isn't really admins on fanpop spots, and everyone can contribute links, videos, تصاویر and anyone can suggest تصاویر for the spots banner and شبیہ etc. There's really no limitation to the شائقین contributions to the spot, even if they didn't make it. So I highly doubt that there's a way for your sister to make آپ admin of the spot. The only thing آپ (and of course all other شائقین as well) can do to prevent the spot going out of control is رپورٹ spammers یا abusive users, and if آپ find dead links, duplicates etc, tell the user who گیا کیا پوسٹ it. Ask that user to change link and so on.

No. Not really. This is unfortunately not possible.

I would suggest talking to one of the F4 یا when آپ want to change the main icon/banner use your sister's account ie get the ورڈ پاس of her