looks like this reimu was not a good mother, and this time, her child was not mentaly developed due to being given nutrients directly to speed its physical growth up.
^ I assume "an owner loved a baby an didnt watch it." should be taken to mean the mother abuses/kills it because it's getting more attention than herself?
Also, the 'not the same type as itself' thing makes me wonder, are there any known examples of 'cuckoo' style behavior among Yukkuri? That is to say a type getting their kid to be brought up by another family in some way? (Rapist alices probably don't count, as all the evidence shows that either the mother kills rape-koyukkuri off, or dies in the process of being refreshed by the alices)