So sorry to hear about Manya. It is so incredibly hard to lose one whether they have been with you for a week or for a decade.
I think you have done a wonderful thing though for both you and your new baby. While clearly Manya cannot be replaced, another baby can give you a dedicated space to put all the love and attention you can no longer give to Manya. There is always one out there in need of it.
Welcome to your lucky new baby!