??? any reference to "under the age of 13" is the VICTIM, not the sex offender. where did you read sex offender under the age of 13 in anything i referenced to you? perhaps i missed it in the extensive research i have done in regards to a calvert case i am working on? hmmm
and YES, if the law enforcement and CSS investigation results in substantiated risks affirmed, the parent can be charged with neglect.
The reason I added a child under the age of thirteen is because that is the only way a parent would be able to be charged with neglect for leaving your child with a sex offender. For that to happen, the "sex offender" would have to be a child under the age of thirteen.
Barring the aformentioned facts, there is no prima facie evidence to support that a registered sex offender presents a substantial risk of harm. The laws you are reading are not representing the criminal aspect of the charge, but the civil part which is in reference to a child in need of assistance.