first of all, spongebob would absolutely dote on phoebe! he's also like, canonically good w caring for children so he can and will babysit for them whenever they need one!

also once mr. krabs is sued for all his money, spongebob won't exactly want/need much of it so he'd honestly give most of his money to orpheus and eurydice to make sure they have a comfortable life! he really mean it when he said he never wants them to worry about food ever again