you dont need anything with nanny. It stays there feeds your baby already and every % aging it also adds a % imprint. no kibble no nothing needed.
Imprinting certain things to 100 % is something where you either work together as a tribe or you need to do it on a weekend and take your time. And if its not worth for you then you just stay with a lower Imprint or you buy the imprint later on for GC.