Amber will absolutely love if Rarity is found because she can easily use this to make her look better. If anyone brings up Rarity again, Amber will wax poetic about how safe, happy, fed, warm, and cozy Rarity is. If anyone brings up Rarity being in the cold, then Amber will insist she's a totally different person now than she was 2 months ago. The old Amber is gone because she's learned so much since then. She will deflect and deny forever, saying everything works out wonderfully in Amber's favor and her animals' favor, because look how happy, warm, safe, and loved Rarity is no matter where she is, thanks to Amber's care and love that made Rarity such a wonderful cat. She might even throw in a bs story about how she contacted the new owner, the new owner complimented Amber on her following, told Amber how amazingly well-taken care of Rarity was which showed what a perfect pet owner Amber is, while telling Amber they were unworthy of taking care of Rarity. Amber, in her graciousness, would tell the new owner that they could have Rarity because the love of her life Tommy is going to move in with her. The new owner would cry and forever feel indebted to Amber's great generosity. Amber will say in a vlog that she's planning on taking monthly trips to Wisconsin just to see Rarity because that's how important Rarity is to her, and the new owner will become Amber's imaginary BFF. She won't portray it in any other way other than positive, there will be overblown stories that are obvious lies, and she won't think anything else no matter what anyone says. Because she's a narcissist who has to protect her ego at any cost and nothing will get through her thick narc skull.
Amber would LOVE the burden of a second dead cat off her shoulders.